While the Old Testament tells of many persons who have more than one wife, the Bible gives no evidence that God has ever sanctioned this practice. God’s view of marriage was established at the very beginning when He instituted the relationship (all Scripture is from the Holman Christian Standard Bible):
So the LORD God caused a deep sleep to come over the man, and he slept. God took one of his ribs and closed the flesh at that place. Then the LORD God made the rib He had taken from the man into a woman and brought her to the man. And the man said, "This one, at last, is bone of my bone, and flesh of my flesh; this one will be called woman, for she was taken from man." This is why a man leaves his father and mother and bonds with his wife, and they become one flesh. Genesis 2:21-24
Notice that God gave Adam only one wife, with the intent that two become one, not three or four, etc.
The Bible’s first mention of polygamy is in reference to Cain’s son Lamech in Gen. 4:19. Cain was the sinful man who was marked, and his sons learned his wickedness. From that point on it became cultural for some of fallen man to become polygamous. But notice that when God saved Noah and his wife, and their sons and their wives, they were all monogamous; if God felt the need for plural wives to propagate the earth, He would have given them more before sending them aboard the ark.
As sinful man began to multiply many men of means became polygamous (the average man didn’t, because it took wealth to support more than one wife). However, when Moses led Israel out of Egypt and God’s laws were brought forth, one thing God made a point of was that, when Israel wanted an earthly king he was to be of higher character than the average man. Of him God said, He must not acquire many wives for himself so that his heart won't go astray. Deut. 17:17.
In the Proverbs we have a couple passages to consider. In the first the context is keeping away from women who are not one’s wife.
...take pleasure in the wife of your youth. A loving doe, a graceful fawn - let her breasts satisfy you; be lost in her love forever. Prov. 5:18b-19. Notice that the writer did not say “wives of your youth,” the implication being that there is only one. And it is that one wife who is to satisfy the man, that he be “ravished with her love.” (KJV)
The next passage is among many general proverbs:
A man who finds a wife finds a good thing and obtains favor from the LORD. Prov. 18:22 Again notice that the proverb does not say “who finds wives finds a good thing,” the implication again being that a good thing is one wife.
Ecclesiastes has one passage that can shed some light also. Chapter 9, verse 9 says, Enjoy life with the wife you love all the days of your fleeting life.... Again the word is “wife” and not “wives.”
Proverbs and Ecclesiastes both approach the marital relationship from the viewpoint of one wife.
In the New Testament Jesus discussed marriage and how the Jews messed up the original plan. He gave the following teaching:
"Haven't you read," He replied, "that He who created them in the beginning made them male and female, and He also said: For this reason a man will leave his father and mother and be joined to his wife, and the two will become one flesh? So they are no longer two, but one flesh. Therefore what God has joined together, man must not separate." Matt. 19:4-6 Notice that Jesus refers right back to Genesis to demonstrate the one man/one woman desire of God.
We can next look at what Paul said in 1 Corinthians 7:2: But because of sexual immorality, each man should have his own wife, and each woman should have her own husband. Notice that Paul did not say “wives” or “husbands”; the meaning is clear that each man is to have but one wife.
When Paul was laying down qualifications for Elders and Deacons, part of the qualification of their character was that they only had one wife (harking back to God’s command for the king to have but one wife):
1 Tim. 3:2 An overseer, therefore must be above reproach, the husband of one wife...
1 Tim. 3:12 Deacons must be husbands of one wife...
Tit. 1:5b-6 ...appoint elders in every town, someone who is blameless, the husband of one wife...
So God’s law has always been one wife per man, but He permitted polygamy as he permits divorce; neither is the original intent for marriage. The depiction of plural marriages in the Bible always show marital troubles, which is expected to happen because women are not wired to share their man!