What Is Adultery According to Scripture?

The English word adultery translates the Hebrew na'aph and the Greek moicheia. Both words describe a specific act: sexual violation of the marriage covenant. Adultery is not a general category of sexual sin. It is covenant-specific. It requires an existing covenant to violate.

This distinction matters more than it might appear. If adultery simply means sex outside of a current legal marriage, then a person who has received a civil divorce has no covenant left to violate and any subsequent sexual partner does not commit adultery with them. That is the assumption most of the modern church operates on. But if adultery means violation of the original covenant, which the text presents as continuing until death or lawful dissolution, then the civil divorce decree does not end the adultery analysis. The covenant does.

The Seventh Commandment

Thou shalt not commit adultery. Exodus 20:14. The commandment stands without qualification. In the ancient Near Eastern context, adultery was understood as a property violation of sorts, a violation of another man's exclusive covenantal right to his wife. It was not merely a matter of private morality. It was a covenant offense with legal consequences under Mosaic law, up to and including death for both parties.

The key is the phrase another man's wife. Adultery requires the involvement of a married woman. A man who has sexual relations with an unmarried woman may commit other offenses under the law, but the text does not call it adultery. Adultery is specifically the violation of the marriage covenant, which requires a marriage to exist.

Jesus and the Adultery of Remarriage

When Jesus says in Matthew 19:9 that a man who divorces his wife and marries another commits adultery, he is applying the adultery category to remarriage. The reason is that the original covenant has not been dissolved by the divorce, only disrupted. The covenant holds. When the man enters a second marriage, he is bringing another woman into sexual union with a man whose covenant with his first wife is still binding. That is adultery in the biblical sense: violation of an existing covenant.

The same logic applies to Luke 16:18, where the man who marries a woman put away from her husband commits adultery. She is still covenantally bound to her first husband. When the second man marries her, he enters a union that violates her existing covenant. That is adultery.

The Adultery of Separation Without Release

Paul's instruction in 1 Corinthians 7:10-11 addresses the wife who departs from her husband without a lawful release. He tells her she must remain unmarried or be reconciled. The reason is the same: the covenant holds. She is still a married woman before God, regardless of what the civil court has said. Any sexual contact with another man while the covenant holds is adultery in the biblical sense, whether or not a second ceremony has taken place.

This is the point most people find hardest to accept. The idea that a woman can be living in adultery without having gone through a second wedding runs against every assumption the modern world holds about divorce. But the text is not structured around modern assumptions. It is structured around the covenant, and the covenant does not dissolve because a court said it did.

What Adultery Is Not

Adultery is not every sexual sin. The biblical text distinguishes adultery from fornication, from prostitution, from other sexual violations. Each category has its own vocabulary and its own legal treatment in the Mosaic system. Collapsing all sexual sin into the category of adultery flattens those distinctions and produces readings that the text does not support.

A man who has sexual relations with a woman who has received a lawful release from her first husband through his initiation of divorce has not committed adultery, because there is no longer an occupied covenant to violate. The first husband dissolved the covenant on his own authority. The woman received genuine release. The second union does not intrude on an active covenant.

The adultery analysis always returns to the same question: is the original covenant still active? If it is, any subsequent sexual union violates it. If it was lawfully dissolved, the analysis changes. The modern church has largely stopped asking that question carefully. The text demands that we ask it every time.