This takes us back to polygamy. Deuteronomy doesn’t explicitly endorse polygamy. It only implies it. And the later prophets show that such an implication is mistaken.
For one, though the Bible doesn’t say the Patriarchs’ polygamy is wrong, it shows it. Read about Abraham and Hagar, or David and Bathsheba, or Jacob and Leah. Again and again, kings and Patriarchs take multiple wives with disastrous consequences. We can read between the lines. Polygamy is shown to be a bad idea, even if it’s not said to be such.
Second, the prophets started using marital imagery to describe God and Israel. God is Israel’s husband. And he has only one chosen people. If God is not polygamous in such analogies, why should Israelites be?
Source: https://www.catholic.com/magazine/online-edition/does-the-bible-permit-polygamyLater Judaism thus started to have doubts about earlier polygamous allowances. By the return from their Babylonian exile, Jews had largely abandoned the practice. And by Rabbinical Judaism, polygamy was completely condemned.
We can go farther. Even if the Old Testament supports polygamy (as we’ve just shown, it doesn’t), the New Testament is what matters most for if its still allowable for us Christians. And plainly, the New Testament doesn’t allow it. Jesus says a man should be joined to his wife, and they will become one flesh (Matt. 19:3-6). Jesus defines adultery as even looking at another woman lustfully (5:27-28). And Paul commands that “each man should have his own wife and each woman her own husband” (1 Cor. 7:2).
A clear picture emerges. Marriage is between two people: one man, and one woman. Polygamy—whether tolerated or condemned in previous generations—is not part of God’s ultimate design.
This should be expected, because polygamy really works only in a culture of male dominion. It doesn’t work if a woman is supposed to be an equal and integral member of family and society, as the Bible clearly teaches. Whose in-laws do we see at Christmastime? Who gets priority when hubby is in the mood? How are the children raised with multiple, equal women acting as mom? How are decisions made? Things inevitably devolve into what actually happened in the Bible’s stories of polygamy: one wife playing second fiddle, one wife domineering, one set of children fading into the background, and one husband with a throbbing headache.
So we can confidently say that biblical marriage is between one man and one woman. Despite the controversy about the “man” and “woman” part of the definition, we need not question the word “one.” Polygamy was once tolerated in God’s plan, but it showed itself prone to domination and domestic strife. And so God’s people abandoned it, and Jesus condemned it. Frankly, I’m happy for that—and so is my wife.
My response will be in the next post. I welcome all others to chime in.