Many of God’s favorite people were polygamists: Abraham, Jacob, Judah, David, Solomon, etc. He did not cut them off from his favor for this."
All we need to do is look at God's original design for marriage, which was one woman for one man. In Genesis, He said He would make a helpmeet--singular---for Adam. Not a couple or a few of them.
The Bible says that God hates divorce, yet sinful human beings disobeyed His intentions there, as well. So He provided guidelines to be used in the event of divorce, knowing that man would continue to distort His will for marriage.
Deuteronomy 17:17 specifically forbids Israel's kings to take multiple wives. Also, polygamy is addressed in Malachi 2.
As for the men you call God's favorite people, they were all sinners, like the rest of us, and some of their sins were described in the Bible. David was an adulterer and a murderer, but neither was sanctioned by God. His grace and love is given in spite of our sins.
Actually, the Bathsheba/Uriah incident supports my position.
Nathan goes to David with a story about a rich man who chooses not to use one of his many own sheep for dinner, but instead takes the pet lamb of a poor man and cooks it up.
There is not a hint here that the rich man is doing wrong because he has many sheep, only that it is wrong for him to take away that of the poor man.
IOW, David's polygamy is accepted as perfectly normal and unexceptional, while his adultery (and resulting murder) is condemned.
I have no problem with the claim that God's original intent was one man/one woman. I have a beef only with those who therefore claim that the OT didn't allow for polygamy, when it obviously did. These were just facts of life in the Middle East of the time, and were accepted as such by the Bible writers.
Well, no it doesn't.
16 The king, moreover, must not acquire great numbers of horses for himself or make the people return to Egypt to get more of them, for the Lord has told you, “You are not to go back that way again.” 17 He must not take many wives, or his heart will be led astray. He must not accumulate large amounts of silver and gold.
This is very obviously a warning against ostentation and decadence. The king is not supposed to take "many wives" for the same reason he is not to accumulate large numbers of horses or large amount of gold and silver, because doing so would require oppression of the people to be able to afford the extravagance.
It also clearly says "many wives," not "more than one wife." Just as the reference to large numbers of horses can't be taken to mean the king should only have one horse.
Also, polygamy is addressed in Malachi 2.
Well, no it's not, or at least that's not the obvious primary meaning of the verse.
14 Yet ye say, Wherefore? Because the Lord hath been witness between thee and the wife of thy youth, against whom thou hast dealt treacherously: yet is she thy companion, and the wife of thy covenant.
Based on other scriptures with similar references, this refers to divorcing the "old wife" in order to marry the hot new number, a practice that is still popular in the USA and unfortunately not unknown among those claiming to be Christians. And of course America has advanced so far women can indulge in it too.
I suppose it could be stretched to include taking an additional wife, but that would be a lot less treacherous than tossing the old one out into the street without a way to support herself.