It’s often argued that the Bible not only allows for polygamy but even endorses it. I’ve seen this argument be made both by unbelievers seeking to undermine Scripture’s moral authority, and heretics just looking to justify their immorality. However, as I’ll demonstrate in this article, regardless of who’s making this argument or for what reasons, the overall thesis is simply false. Contrary to popular belief, the Bible (including and especially the Old Testament) not only doesn’t allow for polygamy, but also consistently condemns the practice whenever it gets the chance. 

To begin, if we want to understand what Scripture teaches about marriage it’s important to examine where it first (explicitly) shows up, Genesis 2:24. This classic text reads, “a man shall leave his father and his mother and hold fast to his wife, and they shall become one flesh.” Although it’s quite obvious, this point often goes unnoticed by most readers: The text says that marriage is when a man holds fast to his wife (singular), not his wives. In the words of James Jordan, “Infidelity, polygamy, and divorce are all forbidden by implication in [this verse]. If a man cleaves or sticks to his wife, he will be unable to cleave to another.” This interpretation is borne out when we read a few chapters ahead and are introduced to the world’s first polygamist, Lamech.

As Seraphim Hamilton demonstrates, Genesis 4:17-24 tracks the line of Cain’s descent into depravity. After Cain commits the first murder, he gives birth to a son named Enoch, which means “City.” Enoch then has a son named Irad, or “Destitute City,” and to him is born Mehujael, “Destroyed of God,” who then bears Methushael, “He Who Kills God,” until finally Lamech is born, whose name simply means “King.” Clearly, Lamech is being portrayed as the culmination of wicked humanity before the Flood (hence why he fathers Noah), and that’s because he’s the fullness of Adam’s fall. In the Garden, Adam tried to seize the Tree of Kingship by force, and in King Lamech, kingship has reached its very worst. That’s why we’re told about Lamech’s polygamy in this context, because it’s a wicked inversion of Adam’s monogamy. 

Although he indeed sinned, forefather Adam remained a faithful servant of Yahweh after his exile from the Garden. Cleaving to his one wife, Adam initially bore two sons, Cain and Abel. However, this God-ordained plan for marriage was reversed when Lamech took two wives and also bore two sons to them, Tubal-Cain and J-Abal (Gen 4:19-22). This contrast between monogamist Adam and polygamist Lamech is then made even more explicit by the fact that they both sing to their wives. After marrying his wife, Adam sang a song praising the image of God in her, “This at last is bone of my bones and flesh of my flesh” (Gen. 2:23), however after marrying his wives, Lamech sang a song defaming the image of God, “You wives of Lamech, listen to what I say: I have killed a man for wounding me” (Gen. 4:23 cf. 9:6). Once again, the text clearly portrays Lamech’s polygamy as an assault on Adam’s God-ordained monogamy, and it’s with this introduction in mind that we should understand the theme of polygamy throughout the rest of Scripture. 

The next time we see polygamy in the Torah is in another story about mankind recapitulating Adam’s fall, Genesis 15-16. As I’ve explained before, these two chapters perfectly map onto Genesis 1-3. Adam was promised that “all trees,” including the Tree of Kingship, would be food for him if he waited patiently (Gen. 1:29). But, taking matters into his own hands, Adam tried to force the blessing of the covenant before it was time (Gen. 3:17). Likewise, in Genesis 15:3-5 God promised to bless Abram with offspring more numerous than the stars of heaven, but just like Adam, Abram was impatient. Instead of waiting for the covenantal blessing to come on God’s terms, Abram took matters into his own hands and tried to force the conception of a child through polygamy with Hagar (Gen. 16:4). Like Adam, Abram tried to have the covenant on his own terms.

Notice how, similar to the portrayal of Lamech, the Torah here uses polygamy as a sign of man’s rebellion against God’s covenant, and specifically the terms of His covenant. Polygamy is the perfect image of this due to its intrinsic opposition to the terms of covenantal marriage, which God ordained to be one man and one woman who become one flesh. Abram having more than one wife was a clear sign that he was living on his own terms, and not God’s. Now, there’s one more instance of polygamy in Genesis that’s worth discussing, however we’re going to circle back to that after first taking a look at where the Torah discusses marriage in (perhaps) the most detail, Leviticus 18.

As I’ve explained before, this chapter condemns violating the “nakedness” of “flesh of flesh” relationships (Lev. 18:6), and in so doing provides a perfect explanation of biblical adoption. In Scripture, adoption allows one to have the exact same relationship to their adoptive family as a biological descendant would. This is how Caleb could be the biological son of Jephunneh (Num. 32:12), but end up on the genealogy of Hezron through adoption into his family (1 Chron. 2:18). Leviticus 18:9 operates on this logic by considering a step-sister to be identical to a biological sister, and Leviticus 18:14 shows how this kind of adoption relates to marriage. This verse condemns sleeping with your father’s brother’s wife (your aunt) as incestuous, even though she’s a woman you have no biological relationship with. However, despite not being a physical relative, through marrying your uncle this woman was given the status of a female family member. 

The implication seems to be that marriage is a kind of adoption, wherein the wife gets adopted into the husband’s family. Even today we still somewhat understand this, which is why it’s typical for a wife to take her husband’s last name after they get married; it’s fundamentally a sign that she’s been adopted into his family. This understanding of marriage is then confirmed by Leviticus 18:15, “You shall not uncover the nakedness of your daughter-in-law (כַּלָּֽתְךָ֖); she is your son’s wife, you shall not uncover her nakedness.” Because a man’s wife has the status of an adopted sister, that man’s father has to treat the woman as if she were his own “flesh of flesh” daughter. In other words, through marriage, husbands and wives share the same parents and can thus truly be considered adopted siblings.

This sheds light on a strange detail that pervades the Song of Songs, namely, the fact that Solomon keeps referring to his wife as his sister. Over and over again Solomon pours out his love for the woman he calls “my sister, my bride” (Song 4:9-10, 12, 5:1), even though we don’t have a record of Solomon ever marrying one of his biological sisters. In light of Scripture’s teaching on adoption, it’s most likely that Solomon’s wife could be called his “sister” because of her marriage-adoption into Solomon’s family. This is further supported by the fact that the word translated as “bride” throughout the Song is “כַּלָּ֔ה,” which is the very word used in Leviticus 18:15 to reference daughter-in-laws. This strongly suggests that the Levitical understanding of marriage-adoption is at play here, demonstrating that, through marriage, the woman of the Song became the daughter of David, and the sister-bride of Solomon.

All of this is crucial to understanding the only passage relevant to polygamy in Leviticus 18, “And you shall not take a woman as a rival wife to her sister, uncovering her nakedness while her sister is still alive” (Lev. 18:18). Although the popular interpretation of this verse is that it only condemns polygamy with the biological sister of one’s wife, we now know that it’s doing much more than this. Because marriage entails the status of an adopted sibling, if a man has two wives then these wives would always be sisters by virtue of being married to the same man, and thereby sharing his father. Leviticus 18:18 is thus a condemnation of polygamy as such, which is why it refers to multiple sister-brides as “rivals” (צָרַר). An almost identical word is used in 1 Samuel 1:6 to describe how Peninnah and Hannah were “rivals” (צָרָה) due to their mutual marriage to Elkanah, however it’s never implied that they were biological sisters. Instead, the reason two sister-brides are rivals isn’t due to their biological lineage, but rather their marriage-adoption to the same man.

Circling back to Genesis, we now have the proper context to explain the patriarch Jacob’s polygamy. James Jordan describes this well: “Jacob had married sisters [Gen. 29], though this involved a trick, because he was legally married to Rachel and then physically cleaved to Leah, thus becoming bound to both without planning to be. Israelites might have imagined, thus, that marrying two sisters was permissible. But God said, ‘And you shall not take a wife in addition to her sister as a rival while she is alive, to uncover her nakedness.’ Any second wife is a rival, and any second wife ‘uncovers the nakedness’ of the first, exposing her to shame and ridicule as inadequate. Thus, this law also forbids all polygamy.” 

Biblical stories involving polygamy (such as Jacob and his wives) in no way serve as an endorsement of the practice, but rather a fearful warning. Because while polygamy is always wrong, it’s also real. In that, if you marry more than one woman you’re actually married to more than one woman (cf. Deut. 21:15), and must treat them both as wives. Indeed, the familial conflict that Jacob’s (sinful but real) polygamy caused is quite literally the driving force behind Joseph’s story in Genesis 37-50, wherein his step-brothers’ jealousy makes them murderous. At this point, however, there’s still one more passage that the pro-polygamist has in his arsenal:

Then Nathan said to David, “You are the man! This is what the Lord, the God of Israel, says: ‘I anointed you king over Israel, and I delivered you from the hand of Saul. I gave your master’s house to you, and your master’s wives into your arms. I gave you all Israel and Judah. And if all this had been too little, I would have given you even more. (2 Samuel‬ ‭12:7-8‬)

On the surface, it seems like God is endorsing polygamy by stating that He actively gave king Saul’s (multiple) wives to king David. However, we know with absolute certainty that this can’t be the intended meaning of the text, not only because of what was discussed above, but also because the Torah explicitly forbids kings from becoming polygamous: “And [the king] shall not acquire many wives for himself, lest his heart turn away” (Deut. 17:17). Polygamy is, in fact, one of the main reasons why the reign of king David’s son, Solomon, was brought to an abrupt end (1 Kg. 11:1-9). So what’s going on here then? Well, remember what was shown above: While polygamy is always sinful, it’s nonetheless real. King Saul indeed violated the Torah by taking multiple wives, however these wives truly belonged to the household of Saul. And since God intended to give the entire royal house of Saul over to David, his wives would naturally be a part of that. Thus, this passage isn’t an endorsement of polygamy, but rather just an acknowledgement of its reality.

So, when it comes to the OT’s teaching on polygamy, here’s what we know: The very first mention of marriage in Scripture has an implicit condemnation of polygamy; the Law of Moses makes this condemnation explicit by forbidding the Israelites (and the king in particular) from engaging in polygamy; and almost every example of polygamy in the OT ends in disaster. By the time we get to the NT, there’s little reason for anyone to reiterate the fact that polygamy is immoral, and yet it’s still heavily implied. In Matthew 19:4-6, our Lord quotes the LXX translation of Genesis 2:4 and affirms that, “‘a man shall leave his father and his mother and hold fast to his wife, and the two shall become one flesh.’ So they are no longer two but one flesh.” When asked about lawful marriage, Jesus only ever speaks in terms of “two” becoming “one,” nowhere does He even dignify polygamous marriage by acknowledging it. 

Likewise, St. Paul’s discussion of marriage in 1 Corinthians 7 simply assumes the standard of monogamous marriage. He only ever addresses the “husband” and the “wife,” never the “wives,” and even goes so far as to recommend that spouses don’t remarry after their current spouse is dead, though it’s allowed (1 Cor. 7:39-40). Paul also provides his own interpretation of Genesis 2:4 in Ephesians 5:31-32, where he teaches that the mystery of one man and one woman coming together in marriage is symbolic of Christ’s marriage to His Bride, the Church. Since we have one faith, one Lord, and one baptism (Eph. 4:5-6), the Church is also one. Hence, the reason why monogamous marriage is the only lawful form of marriage in the NT is because it’s supposed to reflect this relationship between the one Church and her one Lord. This is why St. Paul only allows those in lawful marriages (i.e. marriages that reflect Christ’s marriage to His Bride) to rule the Church: “a bishop must be blameless, the husband of one wife” (1 Tim. 3:2). 

In conclusion, it’s quite clear that neither the OT nor NT allow for polygamy. While the reality of polyganous marriage was indeed acknowledged under the old covenant, it was not only never permitted, but even explicitly condemned several times. Thus, it’s quite fitting that by the time we get to the NT, polygamous marriage isn’t even acknoweged as a real form of marriage. Instead, through the teachings of Moses, Jesus, and St. Paul, the canonical tradition of the Church has always considered polygamy to be a violation of God-ordained marriage, and thus completely unlawful.