It is true that some Old Testament saints practiced polygamy (1 Sam. 1:1–2; 30:5; 2 Sam. 3:2–5). King Solomon tops the list with 700 wives and 300 concubines (1 Kings 11:1–6)! However, it is clear from Scripture that the polygamous marriage structure has built-in tensions and problems (Gen. 29:15–30:24). Even though Solomon’s marriages were really political alliances, the practice cost him dearly when he was an old man.
We must also keep in mind that just because the practice of polygamy is mentioned in the Bible, we cannot conclude that the Lord approves the practice. We know from the first two chapters of Genesis that monogamous heterosexual marriage is God’s plan and design for marriage (Gen. 2:18–25). The Lord’s plan is one man and one woman united in marriage for life. The Lord permitted the practice of polygamy in the Old Testament because of the hardness of men’s hearts, but it never had His approval.