Question:
Answer:
As Jesus makes clear in speaking to the Pharisees and citing Genesis 2:23-24, a man and a woman who marry validly become one, and thus what God has joined together no man should put asunder (Matt. 19:4-6). When the Pharisees object and cite Moses’ certificate of divorce, Jesus tells them that Moses allowed divorce for their hardness of heart, “but from the beginning it was not so” (Matt. 19:8).
So that’s one reason why marriage was different in Old Testament times. In addition, we see the frailty of man otherwise, including in the practice of polygamy and keeping of concubines. But we see that the moral law affirms itself, as moral absolutes substantiate themselves absolutely. Indeed, those who took multiple wives and/or concubines got into trouble for themselves and their children and thus God’s people in general, whether Abraham in fathering a child via Hagar, Jacob in taking multiple, and also King Solomon in taking 700 wives and 300 concubines (1 Kings 11:3), in significant part in attempt to make peace with various peoples as Israel’s king.
What God permits is not necessarily what God sanctions. Indeed, God sometimes lovingly punishes us by giving us our way. Jesus comes in the New Covenant to restore order and raise marriage to the level of a sacrament (see Eph. 5:21-33).