Polygamy is the state of having more than one spouse concurrently. The word segment "poly-" means “multiple” or “many”. There are two forms of polygamy: Polyandry, which is when a woman has more than one husband, and Polygyny, which is when a man has more than one wife. In the Bible the prevalent form of polygamy was polygyny.
Scripture clearly states that men holding positions of leadership in the Christian congregation were to have only one wife (Deuteronomy 17:17, 1 Timothy 3:2, 12, Titus 1:6). Other places in the Bible indicate that men are to have only one wife, and women are to have only one husband (1 Corinthians 7:2, 1 Timothy 5:9). God made only one woman for Adam to be his other half, and only one man to be Eve's other half, and the two of them together were viewed as a complete whole (Genesis 2:18-24). This concept is reinforced in that it takes only one man and one woman to produce children; extra mates are unnecessary. Note, also, that whenever Christ spoke of marriage, he always spoke of it in monogamous terms, never polygamous: Matthew 5:31-32, 18:25, 19:5, 9, 29, Luke 14:26.The only times polygamy occurred in the Bible was when men chose to take the extra wives (Genesis 4:19, Genesis 29:18-29, 1 Samuel 1:2, 2 Chronicles 24:3); it was never due to God ordaining this style of marriage.
DIDN'T GOD GIVE WIVES TO DAVID?
Some people believe that God decreed polygamy, pointing out that Scripture states God "gave" multiple "wives" to king David at 2 Samuel 12:8:
What are we to make of this?
The original Hebrew word used for “bosom” in this passage is the word “cheyq”, which is defined in Strong's Hebrew lexicon as follows:
Putting it another way, this word signifies that the women were put into David's care, but without any sexual or marital connotation. This is why other some Bible versions use the alternative renderings of “keeping” (NKJV), and “care” (NASB).
This "master" whose wives were given into David's bosom was King Saul. We know this because God Himself chose King Saul to be Israel's first king (1 Samuel 9:15-17). And, during Saul's reign, David was a prominent servant in Saul's palace (1 Samuel 16:21), making it so that Saul was David's master. Because Saul constantly went against God's direct orders (1 Samuel 13:1-13, 1 Samuel 15:1-27), God chose to take Saul's family out of the royal line and replace it with David and his descendants instead (1 Samuel 16:1-13).
In other words, Saul was David's master, God took everything away from Saul's line and gave it all into David's keeping as the next king.
And this does not mean that David married any of Saul's women when he took the reign as it only states that they were given into David's keeping, along with everything else that God gave into his keeping. Nowhere will you find that any of David's wives were previously married to Saul. To be left into David's keeping basically meant that they weren't kicked out on the streets. Very likely they were kept to function as servants and helpers around the palace.
This is a point in which some people become confused because Scripture mentions that King Saul had a wife named Ahinoam while also mentioning that David also had a wife named Ahinoam.
The key to this confusion is reading what Scripture states about these women: Saul's Ahinoam was the daughter of Ahimaaz (1 Samuel 14:50), whereas David's Ahinoam was from the region of Jezreel (1 Samuel 25:43). Also, Saul's Ahinoam bore a daughter named Michal (1 Samuel 14:49), who later became a wife of David (1 Samuel 18:27). Since the Jewish law considered it wickedness for a man to take a woman and her daughter in marriage (Leviticus 18:17), God would not have given Saul's Ahinoam over to David for marriage.
It is also important to note many names in the Bible are shared by different people. For example, in the Old Testament there were two King Jeroboams (1 Kings 11:26, 2 Kings 14:16), as well as two Enochs (Genesis 4:17-18, Genesis 5:18) In the New Testament there were two Josephs (John 6:42, Matthew 27:57), and even within the group of apostles there were two Judases (Luke 6:16) and two James (Matthew 10:2-3). Likewise, the Ahinoam married to Saul was a different woman than the one who was married to David.
GOD'S TOLERANCE OF HUMAN NATURE
Although it is clear that God originally intended for marriage to be a monogamous union it is equally clear that the people of those days overstepped this with their polygamy. This causes many people to question: If God does not approve of polygamy, why did He allow so many people to practice it anyway?
This is because we are in the midst of a major issue: Who has the right to Universal Sovereignty. What does this have to do with polygamy? It has to do with letting humanity prove whether we can successfully live under our own rules without God's interference. This means God stays out of our primary "business"; letting us go with our faulty wisdom in order to see whether we have what it takes to successfully rule ourselves. (More details on this matter in Chapter 24, titled “World Suffering). Part of this means tolerating our cultural decisions for polygamy without divine interference.
IS TOLERANCE THE SAME AS APPROVAL?
Keep in mind that allowing polygamy is not the same as approving of it. The Bible shows examples of God allowing a situation even though He didn't actually approve of it. The Moses Divorce Certificate is one example (Mark 10:4 in reference to Deuteronomy 24:1-4). And on two separate occasions God allowed Abram's lies to cause kings to abduct his wife, even though God clearly didn't approve of such things (Genesis 12:14-17, 20:1-6). God even allowed David to make the mistake of taking another man's wife and killing the man, although He didn't approve of these actions either (2 Samuel 11). Therefore, equating allowance with approval is a flawed line of reasoning.
CONSEQUENCES OF POLYGAMY
Because polygamous men were treating some of their wives unfairly God installed laws to protect the additional wives and their children (Exodus 21:7-10, Leviticus 18:18, Deuteronomy 21:15-17). It is also worth noting the problems that came up due to the surplus wives being jealous of one another (Genesis 16:1-6, 29:30-30:15, 1 Samuel 1:1-8).
We must realize that rival situations will emerge in polygyny because women were given a strong desire for their husbands (Genesis 3:16), making it unnatural for a woman to share a husband; and Scripture makes it clear that God does not approve of unnatural situations (Leviticus 18:23, Leviticus 20:12, Romans 1:26-27, 1 Corinthians 6:9, Jude 7). As for polyandry, this too is against what God intended, because He made the man to be the head of the woman (1 Corinthians 11:3, Ephesians 5:23), and a woman can have only one headship, otherwise there will be problems as to whom she should be obedient to if the husbands have differences in their headship. Therefore, multiple marriage is an institution that works against God's will.
It is clear throughout the Bible that polygamy is a version of marriage that God never decreed. Instead, it is a vice of human origin that runs against God's holy standards and creates problems within the family unit. Therefore it is clear that the only form of Godly marriage is that which is monogamous.