Though the Bible does show numerous examples of polygamy, there are is never an example of God condoning this type of relationships. From the beginning, marriage was designed as a union between one man and one woman. The first command of marriage is found in Genesis 2:24:
“Therefore shall a man leave his father and his mother, and shall cleave unto his wife: and they shall be one flesh.” The sanctity of marriage is protected by the Seventh Commandment (Exod. 20:14).
Notice that the scripture above says, his “wife” [singular]. God specifically forbade the kings to practice polygamy, saying, “Neither shall he multiply wives to himself, that his heart turn not away” (Deut. 17:17).
Still, the Old Testament gives many examples of kings marrying multiple wives; in rank defiance of God’s law, which resulted in punishment incurred for this sin. One specific example is that of King David, though he later repented of this sin and put away his wives and his concubines, except one (II Sam. 20:3). These women lived in widowhood for the rest of their days.
Looking to the NT, we find in I Timothy 3:2, that one of the qualifications for a minister is that he be the husband of one wife. A polygamist can’t even serve as a deacon in God’s Church (v. 12). Why is this point so important? Because your Bible states that the marriage relationship is a type of the relationship between Jesus Christ and the Church. He will marry only one Church:
“Let us be glad and rejoice, and give honour to him: for the marriage of the Lamb is come, and his wife [singular] hath made herself ready” (Rev. 19:7).
Christ will marry only one wife, and seeing the multiple examples of Biblical instruction, we can easily deduce that polygamy is a sin in God’s eyes. It was never condoned in Old Testament times, and it is not condoned today.