Biblical Families
The Basic Argument for Christian Plural Marriage
The most fundamental argument from the Bible that Christian plural marriage is permitted is that nowhere in the Bible is it NOT permitted, or criminalized, or punished, or even spoken against. Seriously.
To be fair, you've probably heard stories taught in church that are held up as examples, or proof texts, or justifications for monogamy, and as all of us in the West have come of age in a culture that suppresses polygamy, it doesn't take much 'convincing' for us to nod and simply agree with our teacher that yes, in fact, that does 'prove' it.
On reflection, though, those examples fall apart, and are easily shown to not 'prove' anything. Not if you're serious about logic and evidence and what constitutes proof.
Step One in apprehending what the Bible really teaches about marriage is to realize that the whole case against polygamy in the West is based on inferences drawn from individual stories and the occasional proof text that is generally about marriage but not specifically about polygamy. There is no verse in the Bible that says God disapproves of polygamy.
If your response to that is "yeah, but...", you're going to have a hard time with this. The Bible is chock full of express prohibitions of behaviors, including criminal sanctions all the way up to the death penalty for inappropriate marital or sexual relationships. One might think that if God had a problem with plural marriage He might have mentioned it at least once somewhere in the scriptures. But He didn't, and the silence is deafening. Just let that sink in....
Once you get used to the idea that the Bible has no express prohibition of or punishment for polygamy, Step Two is to realize that in the scriptures polygamous men are routinely held up as being patriarchs and exemplars of the faith, with no critical mention made of their family situation. There are several examples of this, but the most obvious one of the bunch—jaw dropping, really, if you haven't thought this through before—is King David.
2 Samuel 12:7-13 – And Nathan said to David, Thou art the man. Thus saith the LORD God of Israel, I anointed thee king over Israel, and I delivered thee out of the hand of Saul; And I gave thee thy master's house, and thy master's wives into thy bosom, and gave thee the house of Israel and of Judah; and if that had been too little, I would moreover have given unto thee such and such things. Wherefore hast thou despised the commandment of the LORD, to do evil in his sight? thou hast killed Uriah the Hittite with the sword, and hast taken his wife to be thy wife, and hast slain him with the sword of the children of Ammon. Now therefore the sword shall never depart from thine house; because thou hast despised me, and hast taken the wife of Uriah the Hittite to be thy wife. Thus saith the LORD, Behold, I will raise up evil against thee out of thine own house, and I will take thy wives before thine eyes, and give them unto thy neighbour, and he shall lie with thy wives in the sight of this sun. For thou didst it secretly: but I will do this thing before all Israel, and before the sun. And David said unto Nathan, I have sinned against the LORD. (emphasis added)
In this passage, Nathan is confronting David for the grave double sin of adultery and murder, after David knocked up Bath-Sheba and then had her husband killed in an attempt to avoid the consequences of his adultery. As a result, David gets a fitting and just punishment: Because he took another man's wife in secret, God will take his wives before his eyes (which did happen later). Because David had Uriah slain with the sword, God promises that the sword will never leave David's house (and several of his sons were later killed).
But look at what happened in that middle part: "I gave thy master's wives into thy bosom." In the charge against David, one of God's gripes is that he had already given David a bunch of wives, and would have cheerfully given him more "if that had been too little". Have you ever gone back to God and said, "Thanks for the gift, but it's not enough, I want more."? Seems pretty far-fetched for us, but that's exactly what God's inviting here. He had blessed David in so many ways, and would have been willing to do more, so there was never any need for David to steal Uriah's "one little ewe lamb".
What was God's judgment of David's life? Oh, right: "A man after [God's] own heart" (Acts 13:22), who "did that which was right in the eyes of the LORD, and turned not aside from any thing that he commanded him all the days of his life, save only in the matter of Uriah the Hittite" (1 Kings 15:5). According to the Bible, David's eighteen or so wives were not a problem.
So with David, we have a man after God's own heart, doing everything right except for that one thing, and God says that other than that one thing, David did nothing contrary to God's commandments. Further, God says he gave David a bunch of wives and would have given him a bunch more if David would have just asked. Would God have done that if He had a problem with polygamy?
There is no express prohibition of polygamy in scripture. Instead, approved men and women are shown as polygamous without criticism or comment from God (at least not for their polygamy, whatever else they may have gotten in trouble for), and God gives men multiple wives when it suits Him to do so.
The third and final step in this process is that once you realize that the Bible doesn't show us God condemning or criticizing polygamy, and in fact He appears to be fine with it, providing multiple wives on occasion, then you start wondering how it came to pass that the institutional church in the West so firmly rejects plural marriage. There's an answer to that question that we'll develop in more detail elsewhere on this site, but the short version is that a reasonably quick study of church history will identify when and how and why the notion of legally-enforced monogamy crept into the church and then took over. There's a reason we all grew up thinking this way; it just doesn't have anything to do with the Bible.