Bigamy is the crime of marrying while still married to another person; polygamy is having more than one spouse at a time. Can a man be a servant of God and also a bigamist? No, not any more, but where in the New Testament does it say that bigamy and polygamy are sins? The biblical passage of Genesis 25:1-6 reveals that Abraham had concubines in addition to his wife Keturah. A concubine is a wife of second rank in cultures that allow men to have more than one wife. Jacob had two wives (Gen. 29:21-29) and Solomon had hundreds of wives (I Kings 11:1-3). All of these men were servants of God.
Are the above mentioned scriptures confirmation that God allows His male servants to have more than one wife? Obviously, His permissive will during Old Testament times allowed what is now known as bigamy and polygamy. A better question to ask is, "Does God permit His servants to have more than one wife in New Testament (modern) times?" The first truth to realize is that the practice of having multiple wives was never pleasing to the Lord. Does that mean that Abraham was a sinner because he had concubines (secondary wives)? No, because God had not forbidden such a practice as early as Abraham's time. The Lord had not yet given the Law and scripture declares that, "Sin is not imputed when there is no law..." (Rom. 5:13). God's Law was given later, thus prohibition against polygamy appears in Deuteronomy 17:17 which reads, "Neither shall he multiply wives to himself that his heart turn not away...."
Some will argue that this scripture doesn't apply to ordinary servants of God because it was spoken in reference to kings. However, under the New Covenant (Testament), all true followers of Jesus are made kings and priest unto God the Father (Rev. 1:6). Jesus said that the ministers of God through Him under the New Covenant, also called the Kingdom of Heaven, are greater than the greatest minister that served during the Old Testament (Mat. 11:11). This higher service to the Lord does not come without a higher standard by which to live. This is why Jesus said, "Be ye therefore perfect even as your Father which is in heaven is perfect" (Mat. 5:48). The biblical definition of spiritual perfection is explained in the article, Jesus Said, "Be Ye Perfect." What Did He Mean?". Just as the natural kings of the Old Covenant were forbidden to have multiple wives, so the spiritual kings (Christians) under the New are also forbidden. There's not a single New Testament scripture that annuls this commandment.
Did king Solomon sin in having multiple wives or practicing polygamy? The answer is obvious. I Kings 11:1,3,6 and 9 say, "But king Solomon loved many strange women.... And he had seven hundred wives.... And Solomon did evil in the sight of the Lord.... And the Lord was angry with Solomon because his heart was turned from the Lord God of Israel...." Solomon was king David's son so he knew what the Law said. Sin was imputed this time because there was knowledge of God's prohibition of polygamy. Scripture shows that Solomon repented of this evil that he had done.
Jacob having two wives is a unique case. Was he guilty before God of bigamy or polygamy? No, he was not, but why? First, not only did Jacob, like Abraham, live before the giving of God's Law, when the Law came it did not forbid a man to have 2 wives. Scripture does emphasize the number 2 to keep the distinction between 2 spouses and multiple spouses. Believers can be certain that God's Law did not forbid a man to have 2 wives because it actually gave him explicit instructions for how he was to behave towards them (Deut. 21:15).
So, although a Christian man can't have multiple wives, why can't he have 2 wives? Jesus gave the answer to this question when He explained that there were some actions of men that God permitted under the Old Testament that He doesn't allow anymore. This is commonly referred to as the "permissive" will of God in the Old Testament. The apostle Paul repeatedly reminds that the Law of God couldn't be kept by man. Therefore, he could never be counted righteous by the works of the Law which was in place in preparation for the Law of faith in Christ. Paul taught, "...If there had been a law given which could have given life, verily righteousness should have been by the law" (Gal. 3:21).
God knew that man's heart could never be made perfect under a divine law that he couldn't keep in his weakness. Therefore, due to man's imperfection, The Lord allowed certain actions that He will no longer tolerate. Why? Because He has sent His Son who is the perfection of everyone that obeys Him (I Cor. 1:30). One of the things God allowed under the Old Covenant was for a man to put away (divorce) his wife for any reason. Jesus explained that under Grace, such behavior is no longer acceptable because God demands the doing of His perfect, not permissive, will as was done in the beginning (Mat. 19:3-8).
Matthew 19:3-8 says, "The Pharisees also came unto him tempting him and saying unto him, 'Is it lawful for a man to put away his wife for every cause?' And he answered and said unto them, 'Have ye not read that he which made them at the beginning made them male and female. And said, 'For this cause shall a man leave father and mother and shall cleave to his wife and they twain shall be one flesh?' Wherefore they are no more twain, but one flesh. What therefore God hath joined together, let no man put asunder. They say unto him, 'Why did Moses then command to give a writing of divorcement and to put her away?' He saith unto them, 'Moses, because of the hardness of your hearts suffered (allowed) you to put away your wives. But, from the beginning it was not so.'"
It must be observed in the above passage that Jesus said that a man shall cleave to his wife and that they "twain" shall become one flesh. The word "twain" means 2, exactly 2, and no more than 2. This is an amazing glimpse into the thought of the Creator concerning His institution of marriage. Once a man has cleaved to his wife, God sees one flesh composed of male and female. How then can a man that has already cleaved to his wife and become one flesh with her cleave to another female? A second wife would make three people trying to become one flesh. A third wife would make four people trying to become one flesh and so on. Jesus' deliberate use of the word "twain" limited both the number and gender of people who can become one flesh and that is specifically one man and one female wife. Bigamy and Polygamy are sins. It should be remembered that among God's people, the children of Israel, those things that were sins in the eyes of God were also crimes in the eyes of the law of the land. So, how is it that king David could have more than one wife and be in right standing with God? Answers straight from scripture in the article, King David Had More Than One Wife: A Prime Example of Polygamy in the Bible