For generations, Christians have repeated the idea that the moment a man and woman have sex, they are “married in God’s eyes.” It sounds simple, it sounds tidy, and it sounds like a convenient way to discourage fornication. But there is a major problem with this claim: the Bible never teaches it. Not once. In fact, Scripture repeatedly shows the opposite. Sex is the consummation of marriage, not the creation of it. A true marriage begins with covenant, and sex seals that covenant.
Misunderstanding this distinction not only confuses the nature of marriage but also mislabels sin. When we confuse fornication with “marriage,” we obscure biblical categories God has clearly defined.
Sex Does Not Create Marriage: Jesus and the Samaritan Woman
One of the clearest refutations of the sex-equals-marriage idea is Jesus’ interaction with the Samaritan woman in John 4. When Jesus revealed her relational history, He said:
“You have had five husbands, and the man you now have is not your husband.” (John 4:18)
This one sentence demolishes the entire doctrine.
Jesus uses the Greek verb eschēs (aorist of echō, “to have, possess”) to describe her previous five husbands. The aorist identifies completed action in the past. In other words, Jesus says she had five husbands—meaning these were past marriages that had ended. Jesus does not treat her as still married to any of them.
Then Jesus uses the same verb in the present tense—“the man you now have”—to describe the man she was living with. She was in an ongoing sexual relationship. Some try to argue she was merely boarding with a man, but that interpretation collapses under both grammar and context. Echō in relational contexts (such as 1 Corinthians 7:2: “each man should have his own wife”) refers to an ongoing sexual partnership.
Yet Jesus says plainly: “the man you now have is not your husband.”
She was living with him. She was sleeping with him. She was in a sexual relationship. And yet Jesus refused to call it marriage.
If sex automatically created marriage, Jesus’ statement would be impossible.
Even more telling, Jesus did not accuse her of adultery. He treated her current relationship as fornication, not adultery against one of the previous husbands. This only makes sense if marriage is created by covenant, not sex.
The Seduction Law: Sex Does Not Create Marriage
Exodus 22:16–17 reinforces the same truth:
“If a man entices a maid that is not betrothed and lies with her, he shall surely endow her to be his wife.
If her father utterly refuse to give her unto him, he shall pay money according to the dowry of virgins.”
If sex automatically formed a marriage, the father would have nothing to refuse. But God explicitly gives the father the authority to block the marriage even after sex has occurred.
This demonstrates two truths:
- Sex outside covenant is sin—this is God’s unchanging moral law.
- Sex does not create marriage—marriage requires covenantal recognition.
The financial penalty was part of Israel’s civil law as a theocratic nation, but the moral distinction between fornication and marriage remains.
Betrothal: Covenant Before Consummation
The biblical concept of betrothal also proves that covenant—not sex—creates marriage.
Deuteronomy 20:7 says:
“What man is there that hath betrothed a wife, and hath not taken her?”
A betrothed woman is called a wife, even though the marriage has not yet been consummated. She is already married by covenant. Consummation has not yet occurred.
The pattern is unmistakable:
Covenant first, then consummation.
Never the reverse.
Sex does not create marriage; it seals a covenant already made.
Jacob and Leah: A Covenant Made in Darkness
The story of Jacob, Leah, and Rachel further reveals how biblical marriage worked and why sex alone does not create marriage. Jewish tradition and ancient Near Eastern customs shed light on what happened.
According to Jewish legend, Laban had Leah heavily veiled during the evening wedding ceremony. This was a common practice. Brides often remained fully veiled during the vows, with very little speaking. Sisters often sounded similar, and the dim evening light created the perfect opportunity for deception. Jacob entered into a marriage covenant with a veiled woman he believed to be Rachel.
Scripture supports this understanding by emphasizing that it was evening and dark (Genesis 29:23), and that Jacob did not discover the deception until morning (Genesis 29:25). By that point, he had already entered a covenant and consummated it.
This event left such a mark on Jewish tradition that, to this day, Jewish weddings include the bedeken—the groom lifts the bride’s veil before the ceremony to verify her identity. This custom exists explicitly because of Jacob’s experience.
When Jacob confronted Laban, Laban appealed to the local custom that the older daughter must marry first. This was the community’s official recognition of the covenant Jacob had unknowingly made. Jacob accepted Leah because refusing her meant forfeiting Rachel. His acceptance established the marriage covenant; the sexual act only consummated it.
Jacob did not become married because sex magically created a bond. He became married because he entered a covenant—unknowingly but legitimately—and consummated it afterward.
Forced and Compelled Marriages: Covenant Validity Even Without Desire
Another area that clarifies the relationship between sex and marriage is the category of forced or compelled marriages under Israel’s civil law. These passages make many modern Christians uncomfortable, but they reveal something crucial about biblical marriage: the validity of a marriage covenant did not depend on romantic desire or even voluntary willingness. A covenant could be compelled by law, and once established, it was recognized as a real marriage before God.
If a man seduced a virgin, he was obligated to endow her to be his wife unless the father refused. If the father did not refuse, the covenant was forced upon him regardless of how he felt about it (Exodus 22:16–17). This was effectively a biblical “shotgun wedding,” and it was binding.
Similarly, in the case of a man who raped a non-betrothed virgin (Deuteronomy 22:28–29), the man was required to marry her and prohibited from divorcing her. The relationship may have begun in sin, but the covenant created afterward was still recognized as legitimate.
War brides functioned the same way. In Deuteronomy 21:10–14, an Israelite soldier could take a captive woman as a wife after a mandated month of mourning. The woman had no say in the matter. Yet the resulting covenant was treated as a lawful marriage.
These scenarios do not prescribe what Christians should do today. But they do teach a foundational truth: covenant—not desire—makes a marriage. Even when covenant was compelled, it was valid. Sex did not create marriage; covenant did.
Paul’s Teaching: Fornication Is Not Marriage
Finally, Paul’s teaching in 1 Corinthians 6 confirms again that sex does not create marriage:
“Shall I take the members of Christ and make them members of a prostitute? God forbid.”
If sex made a marriage, sleeping with a prostitute would produce a marriage. Paul would then need to command men to remain with the prostitute. Instead, he calls the act fornication and commands believers to flee from it.
Paul recognizes sexual union outside covenant as sin, not marriage.
Conclusion: Covenant Makes Marriage; Sex Consummates It
Throughout Scripture, the message is clear:
- Sex belongs inside marriage
- Sex does not create marriage
- Marriage is created by covenant
- Sex consummates that covenant
- Fornication is not marriage
- Cohabitation is not marriage
- Desire does not create marriage
- Covenant does
Jesus affirmed this distinction with the Samaritan woman. Moses affirmed it through the seduction and rape laws and through the binding nature of betrothal. Jewish tradition preserves it through the veil-lifting custom. Paul affirmed it when discussing sexual sin.
Sex belongs within marriage.
But sex does not make a marriage.
Only covenant does.
Biblical Sexology 