Defining polygamy and countries that allow it
Polygamy in The Christian World
Most Christians oppose the practice of Polygamy, usually associating the practice with the Mormons. However, there are a small, but apparently growing, number of Christians who believe that Polygamy is an acceptable practice.
Polygamy in The Scriptures
The belief that polygamy is an acceptable Biblical practice is largely based not on what God's will is concerning marriage is, but on the fact that there are several examples of polygamy in the Bible, the practice is nowhere explicitly condemned and in fact, there were rules in the Pentateuch that regulated the practice.
The Often Unpleasant Consequences of Polygamy
Polygamy was tolerated, but it almost always had less than desirable consequences, this made evident by taking an closer look at some individual cases.
why was polygamy tolerated and what was God's blueprint for marriage? Is divorce a sin? and legitimate reasons for a divorce
Defining Polygamy: As opposed to monogamy where each person has a maximum of one spouse at any one time, polygamy is a form of marriage in which a person has more than one spouse at the same time. When a man has more than one wife, the relationship is technically called polygyny; when a woman has more than one husband, it is called polyandry. However, in line with common usage, tI have applied the term polygamy only to the practice of a man having more than one wife .
Concubines were women who lived with a man in an arrangement similar to marriage with a recognized social status below that of a wife or wives and without certain privileges. However, although Scripture refers to both wives and concubines, in some fashion, concubines were recognized as wives. In 2 Samuel 12: 11, God tells David what would befall his wives - a prophesy that was fulfilled in his ten concubines.
Legal Status: The legal status of polygamy differs from country to country, although people who indulge in polygamy often use the term marriage regardless of whether it is legally recognized or not. Still others ban polygamy, but make an exception for Muslims since Islam allows polygyny, with the specific limitation that the man can only have up to four wives at any one time. (Note that the Qur'anic verses regarding polygamy came into being after the March 19, 625 AD battle of Uhud, in which many males lost their lives, resulting in a disproportionate number of women to men.)
Polygamy is now illegal in all states and territories of the US.
Countries That Allow Polygamy: Some countries allow polygamy under civil or customary law, other recognize only foreign marriages. However, even in societies which allow polygamy, the actual practice rarely occurs, since taking on more than one wife often requires considerable financial resources, which puts it beyond the means of the vast majority of people in those societies. Since multiple wives are often a status symbol denoting wealth and power, the men most likely to be involved are those with the most economic resources and most status in the community. It may still be common practice among the 180,000 Bedouin of Israel., and is "practiced openly in Jordan, Israel, Syria, Yemen, Iraq, and Iran, as well as some of the Muslim nations of North Africa--including Egypt, Sudan, Morocco, and Algeria. These countries are made of mostly agricultural communities, where women are responsible for working the fields, while men work with the cattle". 
Polygamy in The Christian World
Most Christians oppose the practice of Polygamy, usually associating the practice with -
The Book of Mormon, Joseph Smith and Brigham Young
The Book of Mormon states:
"Wherefore, my brethren, hear me, and hearken to the word of the Lord: For there shall not any man among you have save it be one wife; and concubines he shall have none; For I, the Lord God, delight in the chastity of women. And whoredoms are an abomination before me; thus saith the Lord of Hosts... (Jacob 2:27-30, emphasis added)
In other words, no man should practice polygamy unless directed to do so by the Lord exactly what Joseph Smith said in October 1843
"... I have constantly said no man shall have but one wife at a time, unless the Lord directs otherwise." 
However, this is more than a little confusing because Doctrine and Covenants 132 recorded on the 12th of July 1843 was supposed to be a revelation given through Joseph Smith. It included the principle of plural marriage saying in part that the Lord gave men like Abraham and David their wives and concubines
Abraham, Isaac, and Jacob, as also Moses, David and Solomon, my servants, as touching the principle and doctrine of their having many wives and concubines Abraham received concubines, and they bore him children; and it was accounted unto him for righteousness, because they were given unto him, and he abode in my law; David’s wives and concubines were given unto him of me, by the hand of Nathan, my servant. 
Although it is close to impossible to know exactly how many wives Smith had. In 1887 Andrew Jenson, an assistant church historian of the LDS Church listed 27 women besides Emma Smith - Joseph's first wife. Mormon historian Todd Compton estimates that Smith married at least 33 women and that several of them were simultaneously married to other men. Apparently at least eleven of the wives (33 percent) were only 14 to 20 years old when they married Smith 
Brigham Young stated that not only is a person is damned if they deny polygamy, but will never aspire to become a god. He himself apparently "took 55 wives, who bore him 57 children".  He also made the following statements...
Now if any of you will deny the plurality of wives, and continue to do so, I promise that you will be damned, 
The only men who become Gods, even the Sons of God, are those who enter into polygamy, .
However, although it is not the official web site of the LDS church, Mormon rules now states that "Polygamy is a Biblical concept that was approved by God only when commanded by Him to serve His purposes" and that they "practiced polygamy in the early days of the church, but have not done so for more than 100 years" and anyone found doing so is excommunicated. 
Fundamentalist Mormons broke away from the LDS Church largely because of the church's suspension of new polygynous marriages. While the LDS church believe that the schismatics have no right to call themselves "Mormons", the groups themselves believe they are adhering to the original teachings of founder Joseph Smith.
Apart from the Mormons, there are a small, but apparently growing number of Christians who believe that Polygamy is an acceptable practice. One example of an organization that endorses the practice of polygyny as being Scripturally sound calls itself -
Mark Henkel, founder of the Christian evangelical polygamy organization called TruthBearer.org, which define itself as "A Christ-centered, Spirit-led, Scripture-believing organization for Christian Polygamy", and states that
Christian Polygamy, More specifically, polygyny, and only according to the 100% Bible-believing Christian paradigm, is only about life-long-committed (hence, NON-promiscuous), consensual, NON-abusive, loving Christian MARRIAGE. Because we are Christians in deed and in truth, we, of course, place the GOSPEL and the Scriptures as being "Above All Else" doctrinally.
They also claim that
polygamy is in the Bible. Polygamy is found throughout history. These facts prove that marriage's definition includes plural marriage. Polygyny is a far older traditional marriage than anti-polygamy." 
They provide support for pastors who "have long quietly known the truth of Christian Polygamy, but they have often been isolated and unable - even disallowed - to be bold in their churches", and Bible believing Christians who are "quietly disappointed that their Church or its leadership seem to be blind to so obvious a Scriptural Truth as Christian Polygamy". The TruthBearer.org organization provides them with assurance that they are "not alone," and support when the time is right for them in bringing the issue to their churches in the most Christ-like loving and effective manner. 
Polygamy in The Scriptures -
The belief that Polygamy is an acceptable Biblical practice is largely based not on what God's will is concerning marriage is, but on the fact that there are several examples of polygamy in the Bible, the practice is nowhere explicitly condemned and in fact, there were rules in the Pentateuch that regulated the practice.
The Examples Of Polygamy In The Bible.
The first case of polygamy chronicled in the Scriptures is when Lamech, a descendant of Cain, "took to himself two wives" (Genesis 4:19). Esau had several wives as did Elkanah - Hannah's husband and Samuel's father, Gideon said to have had many wives and 70 sons (Judges 8:30). Rehoboam, successor to Solomon's throne had a total of eighteen wives, and threescore (sixty) concubines (2 Chronicles 11:21). David had several wives and concubines. Two of the giants of Old Testament history - Abraham and Moses were also said to be polygamists.
Among the Patriarchs usually listed as polygamists are two giants of Old Testament history.. Abraham and Moses. Based on isolated verses, most people come to the conclusion that both of them had more than one wife at the same time. However when one examines the circumstances in a little more detail, the picture is not quite as clear. In both cases it can not be definitively stated that they were polygamists. See Abraham Below and Footnote on Moses
In any case, using the examples of polygamy in the Scriptures as a guideline for our behavior is an unsound practice. The Bible is a factual written account of important or historical events as they occurred. It makes no attempt to minimize or cover up the sins or failings of the people who's stories are told, nor does it seek to exaggerate their good qualities. Just because Scripture records an action, it does not mean that God approves of that action.
No Explicit Condemnation: One question that has plagued monogamous Christians is why God didn't stop polygamy, or even directly rebuke the men who practiced it. They were never directly charged with any wrongdoing for having multiple wives. Even David, who God called a man after his own heart, was heavily disciplined by God for his adulterous relationship, but never for his multiple wives.
In fact marriages to additional spouses were considered valid in the Scriptures (Jesus' lineage did not always go through the first wife). The only passages in the OT laws that prohibit polygamous marriages are those that would constitute incest. When a man married a woman all her relatives became his kinsfolk thus a man could not marry a woman and her daughter or granddaughter (Leviticus 18:17), a woman and her sister as a rival (v. 18), or a woman and her mother (20:14).
However, it is to be noted that polygamy was not the only wrong doing in the Bible that went unmentioned by God. Abraham's half-lies about his wife Sarah's relationship to him, Lot's selfishness in choosing the better land, Rebekah's scheming to deceive the then-blind Isaac into giving Jacob the blessing that would otherwise have gone to Esau (Genesis 27:1-40). Rachel's stealing of the teraphim that belonged to her father (Genesis 31:19). etc. etc. Just because there never was a specific rebuke by God on every one of these issues does not mean He approved of any of them.
Regulation of Polygamy: Some laws in the Pentateuch do appear to place God's stamp of approval on polygamy. For example note the rules and guidelines concerning the treatment of multiple wives. The laws pecifically prohibiting ill-treatment of the first wife after a second marriage and protected the inheritance of the first born, if he happened to be the son of a less favored, wife.
If he takes another wife to himself, he shall not diminish her food, her clothing, or her marital rights, (Exodus 21:10)
If a man has two wives, the one loved and the other unloved, and both the loved and the unloved have borne him sons, if the firstborn son belongs to the unloved, then it shall be in the day he wills what he has to his sons, he cannot make the son of the loved the firstborn before the son of the unloved, who is the firstborn. "But he shall acknowledge the firstborn, the son of the unloved, by giving him a double portion of all that he has, for he is the beginning of his strength; to him belongs the right of the firstborn. (Deuteronomy 21:15-17 NASB)
It was an obligation for men to marry their widowed sisters in law and support her family. (Deuteronomy 25:5-10) The point being that the brother could very well have already been married.
However, as said above, although God permitted and regulated polygamy, it does not mean that He ever condoned the practice.
Polygamy In The Bible Was Far From The Norm:
What is almost completely ignored is the fact that there are only about eighteen specific examples of polygamy throughout the Old Testament which means the practice was far from the norm. Little is said about the number of Old Testament men of God who had only one wife - For example Adam (Genesis 2-4), Noah (Genesis 6:18), Isaac (Genesis 25:20-23), Joseph Genesis 41:45), Boaz (Ruth 4), Job (Job 1) who was, in fact, a prime candidate for multiple marriages since he was very wealthy and considered "the greatest man among all the people of the East". However even he had only one wife. Next to nothing is known about the personal life of the prophets, but both Isaiah (Isaiah 8:3), and Hosea (Hosea 3:1-3) are specifically said to have been married to one woman.
Additionally, most examples of polygamy in the Old Testament are far from positive. The tragic stories of Abraham, Jacob, Elkanah, David, and Solomon paint such a negative picture of polygamy that it is difficult to see how anyone can come away with a positive outlook. Note: It would be a mistake to assume that just because we are told nothing of the circumstances of polygamists like Gideon or Jehoiada, their households had no problems.
The Often Unpleasant Consequences of Polygamy
Polygamy was tolerated, but it almost always had less than desirable consequences, this made evident by taking an closer look at some individual cases.
Abraham, Sarah and Hagar:
Abraham was married twice. However, Sarah's death is recorded in Genesis 23:1-2, but it is not until Genesis 25,that we are told that Abraham married Keturah and had six sons by her. While it is true that Hebrew composition does not always place events in chronological order, the narrative here does seem to be in the order of time. However, the fact that Keturah is called a concubine in Genesis 25:6 and 1 Chronicles 1:32 may imply that Sarah was still alive,
The main reason that Abraham consistently makes the list of Biblical polygamists is probably because he had a son by Sarah's maid Hagar. However, Sarah herself gave him Hagar. While there is no question that Abraham yielded to temptation, unquestionably Sarah's action played a key role in the whole affair.
Abraham's bearing a son by Hagar brought nothing but trouble for everyone involved. From the time Hagar became pregnant there was tension and jealousy between her and Sarah. She despised Sarah (Genesis 16:4) who then treated Hagar so harshly that Hagar fled (v. 6). Later, because Hagar's son Ishmael began to mock Isaac (Genesis 21:9), Sarah asked Abraham to drive them away (V. 10). This caused great anguish for Abraham, who cared for his son Ishmael (V. 11). All this ended only when God ordered Abraham to send Hagar and her son away. One can only imagine the bitterness and resentment that this must have caused Hagar.
Jacob, Rachel and Leah:
Jacob, who's very name means "supplanter" was patriarch and founder of the twelve tribes of Israel who did not have very auspicious beginnings. He and Esau were fraternal twins born to Isaac, son of Abraham. Jacob, with the help of his mother Rebekah, deceptively acquired the birthright that lawfully belonged to the first born brother.. Esau.
Even though Jacob, in his earlier years, seemed to have faults aplenty, was he also guilty of simply taking to wife any woman he fancied? The answer to that is a resounding no! Jacob became a polygamist because of his father in law Laban's deception and wound up taking two concubines on the instigation of his two wives. All this against a sad backdrop of favoritism, bitterness, jealousy and rivalry.
Jacob fell in love with Rachel and worked for her father Laban for many years in order to win her hand. However Laban deceived Jacob and substituted his other daughter Leah in Rachel's place with the excuse that it was not their custom to give the younger in marriage before the elder.. Since he was the victim of fraud, Jacob probably had grounds to reject this marriage, but did not. He accepted Leah but apparently could not give Rachel up, eventually marrying her as well.
The point of the story is this.. Jacob's initial polygamous marriage to Rachel was the result of him being deceived by her father Laban. Should Jacob have acted differently? Certainly! But he was not willing to give up the love of his life, and since polygamy was not unknown in the day, rightly or wrongly, decided to marry Rachel as well.
Because Jacob loved Leah less than Rachel (Genesis 29:30), God opened Leah's womb, with the result that she bore four sons consecutively. Rachel who remained barren got very jealous of her sister and got Jacob to give her children through her handmaid Bilhah, At this Leah, who apparently was not getting pregnant again, gave her handmaid Zilpah to Jacob to have even more children. There seemed to be no end to the strife and bitterness between the two sisters, with Leah obviously very unhappy because she thought herself "hated" and wanted sons to win the affections of her husband. Jacob also favored his and Rachel's son Joseph who was "the son of his old age". (Genesis 37:3), This causes Jacob's other sons to hate him and eventually sell him into slavery (V. 28).
Elkanah, Peninnah and Hannah: Elkanah loved his wife Hannah more than his wife Peninnah even though Peninnah had given him children and Hannah had not had a child (1 Samuel 1:1–5). Hannah was severely provoked by Peninnah (1 Samuel 1:6-7), which caused her no end of distress (v. 7).
If you wish, copy and paste the following URL's into your browser. Polygamy victims share their horror https://culteducation.com/group/1099-polygamist-groups/16560-polygamy-victims-share-their-horror-.html
David: The story of David, a man "after God's own heart" (1 Samuel 13:14; cf. 1 Kings 11:4) overflows with conflict and turmoil that stemmed from the affair with Bathsheba and the relationships and rivalry among David's children by various wives.
For example, David's firstborn Amnon raped his half sister Tamar, sister of Absalom (2 Samuel 13:1–20). Absalom's response is pure hatred (2 Samuel 13: 21–22), which led him to kill Amnon in a complicated plot (2 Samuel 13: 28–29). Later, Absalom revolted against his father David (2 Samuel 15:1–12) and publicly disgraces David by committing adultery with David's concubines on the roof of the King's palace in full view of Israel (2 Samuel 16:21–22). Absalom is eventually murdered by David's nephew Joab (2 Samuel 18:32-33). At the end of David's life Adonijah, another son by yet another wife, aspires to be king, causing more problems for David until Solomon (his son by Bathsheba) is finally crowned king of Israel (1 Kings 1:5–53).
In the final analysis David suffered a tarnished reputation, a kingdom in shambles, a disgraced daughter, several disgraced concubines, and four dead sons.
Did God Really Give David Saul's Wives?
As He did with the polygamous patriarchs, not only did God never directly condemn David's polygamy, but one passage in particular seems to indicate that God gave Saul's wives to David as a way of blessing him. In 2 Samuel 12, after David has committed adultery with Bathsheba, murdered her husband Uriah, and taken her as his wife, Nathan the prophet confronts David with his sin:
Nathan then said to David, "You are the man! Thus says the Lord God of Israel, 'It is I who anointed you king over Israel and it is I who delivered you from the hand of Saul. 'I also gave you your master's house and your master's wives Heb. ishshah )into your care, and I gave you the house of Israel and Judah; and if that had been too little, I would have added to you many more things like these! (2 Samuel 12:7-8 NASB)
In the passages quoted above God recounts all the blessing He has bestowed on David... anointing David king over Israel; delivering David from the hand of Saul etc. Crucial to the pro-polygamy argument is the fact that God seemed to be telling David that Saul's wives are one of the blessings He had given David. However, the Scriptures only mention Saul as having one wife and one concubine. God could not have given David wives that Saul did not have
The name of Saul's wife was Ahinoam the daughter of Ahimaaz... (1 Samuel 14:50 NASB)
Now Saul had a concubine whose name was Rizpah, the daughter of Aiah... (2 Samuel 3:7 NASB)
However the Hebrew ishshah does not necessarily mean 'wife' but can also mean a woman. For example,
Then Samson went down to Timnah and saw a woman (Heb. ishshah) in Timnah, one of the daughters of the Philistines. So he came back and told his father and mother, "I saw a woman (Heb. ishshah) in Timnah, one of the daughters of the Philistines; now therefore, get her for me as a wife (Heb. ishshah) ." (Judges 14:1-2 NASB)
and does not eat at the mountain shrines or lift up his eyes to the idols of the house of Israel, or defile his neighbor's wife (Heb. ishshah) or approach a woman (Heb. ishshah) during her menstrual period (Ezekiel 18:6 NASB)
To Absalom there were born three sons, and one daughter whose name was Tamar; she was a woman (Heb. ishshah) of beautiful appearance. (2 Samuel 14:27 NASB)
Miriam the prophetess, Aaron's sister, took the timbrel in her hand, and all the women (Heb. ishshah) went out after her with timbrels and with dancing. (Exodus 15:20 NASB)
In those days possession of all property including the harem was a sure proof that the successor (or conqueror) had all legal rights. Since God could not have given into David's hands wives that Saul did not have, it is possible that the term "wives" meant Ahinoam - Saul's legal wife and Rizpah his concubine. or even that God had given David absolute power over every thing possessed by Saul, including female servants.
Certainly there is absolutely no evidence that David had any relations with either Saul's wife or his concubine.
Solomon: Solomon was one of the most celebrated polygamists in all history, and those arguing in favor of polygamy frequently hold him up as proof for the practice of polygamy being right.
What seems to be rarely considered is that Solomon's multiple marriages proved to be the downfall of Israel that was split up as a direct consequence. It is also amazing that neither his son nor his grandson learned anything from this, but each went on to become polygamists in their own right. In fact 2 Chronicles 11:23 tells us that Solomon's son and successor Rehoboam sought many wives for his 28 sons.
The Three Prohibitions (multiplying horses, wives, and wealth)
In Deuteronomy 17:15 the Lord told the people that they would set a king over themselves that the Lord had chosen. He would be from amongst them and not a foreigner. God also added a warning...
"Moreover, he shall not multiply horses for himself, nor shall he cause the people to return to Egypt to multiply horses, since the Lord has said to you, 'You shall never again return that way.' "He shall not multiply wives for himself, or else his heart will turn away; nor shall he greatly increase silver and gold for himself. (Deuteronomy 17:16-17 NASB)
As king of Israel Solomon was bound by these three prohibitions however he disobeyed in all three areas accumulating forty thousand stalls of horses; unparalleled riches; and innumerable wives (See I Kings 4:26; I Kings10: 14-29, I Kings 11:3)
Wives: If read carefully, verse 17 says "He shall not multiply wives for himself, or else his heart will turn away". And this was nothing new but simply a repeat of the warning in Deuteronomy when God banned marriages between the Israelites and other nations.
"Furthermore, you shall not intermarry with them; you shall not give your daughters to their sons, nor shall you take their daughters for your sons. "For they will turn your sons away from following Me to serve other gods; then the anger of the Lord will be kindled against you and He will quickly destroy you. (Deuteronomy 7:3-4 NASB)
We see marriage as a unique bond between two people who are in love however European and Eastern rulers frequently married for political, economic, or diplomatic reasons. Arranged marriages between kings or clan leaders were tools to cement political alliances and often seen as an important way to bind together two countries in both peace and war.
However, foreign wives could (and frequently did) introduce their own customs and idolatry into the nation. For Israel this would have been a death knell, which is why intermarriage was strictly forbidden. Solomon's marriage to Pharaoh's daughter did not draw Solomon away from God into idolatry. (1 Kings 3:1,3). Sadly this did not continue.. As he accumulated more and more wives, he was turned away from the one true God to false ones.
He had seven hundred wives, princesses, and three hundred concubines, and his wives turned his heart away. For when Solomon was old, his wives turned his heart away after other gods; and his heart was not wholly devoted to the Lord his God, as the heart of David his father had been. For Solomon went after Ashtoreth the goddess of the Sidonians and after Milcom the detestable idol of the Ammonites. Solomon did what was evil in the sight of the Lord, and did not follow the Lord fully, as David his father had done. Then Solomon built a high place for Chemosh the detestable idol of Moab, on the mountain which is east of Jerusalem, and for Molech the detestable idol of the sons of Ammon. Thus also he did for all his foreign wives, who burned incense and sacrificed to their gods. (1 Kings 11:3-8 NASB)
Solomon's multiple marriages led to the downfall of Israel. With the exception of one tribe, God took the kingdom out of his hand. See 1 Kings 11:9-13.
Wealth: Considering that many of the men in the Old Testament were very wealthy, and that God Himself gave Solomon "both riches and honor" (1Kings 3:13), it is certain that the king of Israel was never meant to be paupers with one horse. Since God could not have been issuing a blanket warning against wealth, we have to look into the underlying principle.
Vast accumulation of treasure by a king could hardly be effected without oppression. This certainly seemed true in the case of Solomon. The Scriptures tell us that when his son Rehoboam returned from Egypt
So they sent and summoned him. When Jeroboam and all Israel came, they spoke to Rehoboam, saying, "Your father made our yoke hard; now therefore lighten the hard service of your father and his heavy yoke which he put on us, and we will serve you." (2 Chronicles 10:3-4 NASB)
This of course was ignored by Rehoboam, which ultimately led to the division of the country.. His own tribe Judah, alone remaining faithful to him.
Horses and Prestige: Obviously the use and ownership of horses could not have been absolutely prohibited. However, it is possible that in a country where asses and mules were the most common, horses could not only accord the owner with a great deal of prestige, but cause him to trust too much in them.
Some boast in chariots and some in horses, But we will boast in the name of the Lord, our God. (Psalms 20:7 NASB)
A horse is a false hope for victory; Nor does it deliver anyone by its great strength. (Psalms 33:17 NASB)
In summary, the kings of Israel were being warned against indulging in anything that would divert them from their first responsibility.. their service to God. There can be little doubt that riches, prestige, and pleasures are three of the greatest hindrances to godliness.
Why Was Polygamy Tolerated?
If divorce went against the original design for marriage but was tolerated for a while, there is absolutely no reason to believe that the practice of polygamy was any different.
Perhaps at one time, social conditions did exist which made polygamy a "necessary evil." However, for the most part, none of those conditions have carried over into our modern world which is vastly different from the ancient Near East. And, as mentioned earlier, polygamy was not the only wrong doing in the Bible that God said nothing about it in the Old Testament.
Is Divorce a Sin?
Sin is a transgression of God's law, therefore if God had ever issued a commandment against divorce and polygamy then anyone who got divorced or married more than one wife would have been a sinner. However, although the Lord said He hated divorce He never specifically banned it nor did He ban polygamy. Thus neither one was a sin.
Besides which, it is impossible that Moses would have allowed divorce for any reason whatsoever if it had been a sin.
God's Blueprint For Marriage
The question that has to concern the New Testament believer is not what Jacob or Elkanah did, but what God's original design for marriage was.
Christ made it very clear that a permanent union between one man and one woman is God's ideal. When the Pharisees approached Him asking whether or not divorce was lawful, Jesus' answer probably didn't please them because He made it clear although it was tolerated for a time divorce was wholly inconsistent with the original design of marriage. He cited the Genesis creation account - 1:27 and 2:24, in particular where it says 'two will become one flesh'. He also explained why Moses allowed divorce.
Some Pharisees came to Jesus, testing Him and asking, "Is it lawful for a man to divorce his wife for any reason at all?" And He answered and said, "Have you not read that He who created them from the beginning made them male and female, and said, 'for this reason a man shall leave his father and mother and be joined to his wife, and the two shall become one flesh'? "So they are no longer two, but one flesh. What therefore God has joined together, let no man separate." They *said to Him, "Why then did Moses command to give her a certificate of divorce and send her away?" He *said to them, "Because of your hardness of heart Moses permitted you to divorce your wives; but from the beginning it has not been this way. "And I say to you, whoever divorces his wife, except for immorality, and marries another woman commits adultery." (Matthew 19:3-9 NASB)
were to be monogamous
An overseer, then, must be above reproach, the husband of one wife, temperate, prudent, respectable, hospitable, able to teach, (1 Timothy 3:2 NASB)
namely, if any man is above reproach, the husband of one wife, having children who believe, not accused of dissipation or rebellion. (Titus 1:6 NASB)
One Man - One Bride
1 Corinthians 7:2 makes it very clear that marriage is between one man and one woman.
"But because of immoralities, each man is to have his own wife, and each woman is to have her own husband. The husband must fulfill his duty to his wife, and likewise also the wife to her husband." (1 Corinthians 7:2-3 NASB)
Paul calls the Church the bride of Christ and John speaks of marriage of the Lamb, where the bride is the church and the Lamb is Christ. Although this bride of Christ is made up of innumerable Christians, it is never referred to in the plural, but always in the singular. One bride - one wife.
For I am jealous for you with a godly jealousy; for I betrothed you to one husband, so that to Christ I might present you as a pure virgin. (2 Corinthians 11:2 NASB)
"Let us rejoice and be glad and give the glory to Him, for the marriage of the Lamb has come and His bride has made herself ready." It was given to her to clothe herself in fine linen, bright and clean; for the fine linen is the righteous acts of the saints. (Revelation 19:7-8 NASB)
In Ephesians 5 Paul quoting Genesis 2:24 telling the church "for this reason a man shall leave his father and mother and shall be joined to his wife, and the two shall become one flesh" (V. 31). He then went on to tell them that each individual among them was to "love his own wife even as himself, and the wife must see to it that she respects her husband". (V. 33) Both Husband and wife were in the singular.
Legitimate Reasons for A Divorce
1 Corinthians 7:2 makes it very clear that marriage is between one man and one woman. There were only two "exceptions" to the no divorce policy of the Bible - If a spouse dies (Romans 7:2-3) or commits adultery (Matthew 19:8-9).
While it is true that God says He hates divorce, situations in our so called "civilized" age are that make even divorce a "necessary evil" that God would not condemn. Battered spouses and abused children come to mind. Anyone who think that divorce is out of the question in these kind of cases is out of his or her mind, and seems to believe God is as well
Do Any of God's Rules Change?
There are those that believe that God's rules never change, however this is open to challenge.
... Adam and Eve did not eat meat before the flood (Genesis 1:29-30). But after the flood, man was allowed to eat meat (Genesis 9:3-4). When the Law of Moses was given, certain kinds of meat could be eaten, while others were prohibited as unclean. And then, in Mark 7:19 and Acts 10 & 11, God made it clear that "all foods were now clean." In other words, the unchanging God does incorporate change in the way He deals with men, even though He remains the same. The same could be said for the observance of the Sabbath. Violating the Sabbath was once a capital crime (Numbers 15:32-36), but later became a matter of personal conviction (Romans 14:5). 
However, it has to be noted that God's moral laws have never changed. Theft, adultery, fraud, bearing false witness against another, murder, idolatry etc. are sins that if unrepented of, will keep us out of His kingdom.
All of which leaves us with...
A Thorny Problem
Polygamy presents a problem in cases when converts to Christianity already have more than one wife. While no man who has more than one wife can hold an official position in the church, one has to fall back on 1 Corinthians 7, in which Paul instructs the Corinthians to remain in the circumstances in which they came to faith.
This does not include remaining in sin (Romans 6:1). For example the prostitute and thief have to repent of and completely forsake their sin. Since it can not be Biblically proved that polygamy is sinful, the convert should be allowed to remain in the same situation he or she was in at the time of conversion.
 Polygamy: Not as Rare as You May Think. BY: Peggy Fletcher Stack. The Salt Lake Tribune.
 Teachings of the Prophet Joseph Smith, Page 324, October 5th 1843 D.H.C. 6:46. Publisher: Deseret Book Co (June 1, 1977)
 Church of Jesus Christ of Latter-day Saints. Doctrine and Covenants 132.
 Todd M. Compton. In Sacred Loneliness: The Plural Wives of Joseph Smith. Prologue. Page 11.
Publisher: Signature Books (December 15, 1997)
 Scott Anderson. The Polygamists. National Geographic Magazine - February 2010. http://www.truthandgrace.com/polygamy.htm
 Journal of Discourses, vol. 3, p. 266. July 14, 1855. http://jhuston.com/Documents/jd3.pdf
 Journal of Discourses, vol. 11, p. 269. August 19, 1866. http://www.jhuston.com/Documents/jd11.pdf
 Mormon Rules. Mormon Polygamy Today. https://mormonrules.com/list/do-mormons-practice-polygamy-today
 What Insights Do You Have For Missionaries Trying To Address Polygamy In Polygamous Cultures?
FootNote I - Moses
Pro-polygamists believe that the Bible records that Moses had two wives.
Moses was willing to dwell with the man, and he gave his daughter Zipporah to Moses. (Exodus 2:21 NASB)
Then Miriam and Aaron spoke against Moses because of the Cushite woman whom he had married (for he had married a Cushite woman); (Numbers 12:1 NASB)
Some say that when Numbers 12:1 speaks of a "Cushite woman" it is actually referring to Moses' wife, Zipporah. However this is extremely unlikely. Why would Zipporah be called a Cushite in Numbers 12 when her father is called a Midianite in Numbers 10. Besides which, not only does the text imply that Moses' marriage to a Cushite woman was a recent one, but it seems hard to believe that Miriam was objecting to Moses' marriage to Zipporah which had taken place years earlier, and had already produced two children.
Others say that perhaps Zipporah had died and Moses had remarried. While this is possible, it too is unlikely since only a short time had elapsed between the story of the reappearance of Zipporah (Exodus 18) and Moses marriage to the Cushite wife in Numbers 12.
But let us return to the occasion when the Scriptures tell us that Moses sent Zipporah away but Jethro, priest of Midian later brought her and her two sons back to Moses. Note that according to Exodus 2:18 Reuel was Zipporah's father. Although Jethro is called Moses' father in law, in the verses above and in Exodus 3:1, châthân seems to be a general term for a relative by marriage, with a precise relationship determined only by context. For example, châthân is used for Lot son's in law in Genesis 19:14.
Now Jethro, the priest of Midian, Moses' father-in-law (Heb. châthân), heard of all that God had done for Moses and for Israel His people, how the Lord had brought Israel out of Egypt. Jethro, Moses' father-in-law (Heb. châthân) , took Moses' wife Zipporah, after he had sent her away (Heb. shâlach), (Exodus 18:1-2 NASB)
The Hebrew word shâlach rendered "sent away" is frequently used in connection with divorce as the following examples show -
then the man who lay with her shall give to the girl's father fifty shekels of silver, and she shall become his wife because he has violated her; he cannot divorce (Heb. shâlach) her all his days. (Deuteronomy 22:29 NASB)
When a man takes a wife and marries her, and it happens that she finds no favor in his eyes because he has found some indecency in her, and he writes her a certificate of divorce and puts it in her hand and sends her out (Heb. shâlach) from his house, (Deuteronomy 24:1 NASB)
God says, "If a husband divorces (Heb. shâlach) his wife And she goes from him And belongs to another man, Will he still return to her? Will not that land be completely polluted? But you are a harlot with many lovers; Yet you turn to Me," declares the Lord. (Jeremiah 3:1 NASB)
For I hate divorce (Heb. shâlach) ," says the Lord, the God of Israel, "and him who covers his garment with wrong," says the Lord of hosts. "So take heed to your spirit, that you do not deal treacherously." (Malachi 2:16 NASB)
It is therefore entirely possible that Moses and Zipporah were divorced after which Moses married the Cushite woman. We are not told whether Zipporah stayed behind with Moses because she is never mentioned again. Stating that Moses knowingly married two women at the same time is no more than an assumption.
We have absolutely no idea why Moses might have divorced Zipporah, unless it was to break the bonds with the Midianites who were Baal worshippers. When Moses was in hiding from the Egyptians he made his home among the Midianites, who were a semi-nomadic people with remote pastures probably beyond the reach of the Egyptian authorities. Along with the Moabites, they became one of the major enemies of the people of Israel as they made their way out of Egypt. The Lord commanded Moses to war against them (Numbers 31:7), which was the second time that Moses was forced to fight people that he once regarded as his own. [PLACE IN TEXT]