The Law defined it unevenly and aimed the penalty at women in practice. Jesus levels it, and then moves the whole question somewhere harder.
Ask what is adultery in the Bible and the plain answer is sexual unfaithfulness involving a married person. But the Law defined it unevenly, and that unevenness is in the text.
A married woman with any man was adultery. A married man was in breach only if the woman belonged to another man. Jesus removes the asymmetry outright in Mark 10:11 and 12, and then moves the question somewhere harder.
So this is not a page about a rule everybody already knows. It is about what the rule was protecting, who it protected, and what changed.
You shall not commit adultery. Seventh of the ten, sitting between murder and theft, which locates it among the offences that break a community rather than among ritual matters.
The penalty falls on both the man and the woman. The text is even-handed about the sentence even where the definition is not.
A set of cases distinguishing consent from assault, including a provision that a woman forced in open country is not guilty and the man alone answers for it.
A ritual for a husband who suspects his wife, with no equivalent running the other way. Whatever else it was for, only one spouse could be put through it.
Behind the asymmetry is a society organised around household lines of descent. That is the honest historical explanation, and it is also exactly what Jesus declines to preserve.
Jesus does something unexpected twice on this subject, and the second one usually gets all the attention while the first is more radical.
Mark 10:11 and 12. A man who divorces his wife and marries another commits adultery against her. Against her. That category did not exist in the legal system he was speaking into.
Matthew 5:27 and 28. Amy Oden notes Jesus connects the dots “from outward acts to internal orientation, from murder to anger, from adultery to lust”.
Matthew 5:28 is spoken to men about their own looking. In a culture that policed women's appearance, the instruction is pointed at the person doing the looking.
In John 8 a woman is brought caught in the act. Adultery takes two, and the Law they cite names both. Only one is standing there.
On that last passage, the honest note: John 7:53 to 8:11 is absent from the earliest Greek manuscripts and every good modern Bible tells you so in a footnote. Many scholars still think it preserves a genuine memory of Jesus that circulated separately. You should hear that here rather than from somebody using it to unsettle you.
Every post here is free to read. If this one helped you, you can help keep it that way. Pick an amount and finish on Stripe's secure checkout.
Change your amount, update your card, or cancel anytime. Enter the email you give with and Stripe sends you a secure link.
Manage My Giving"Each of you should give what you have decided in your heart to give, not reluctantly or under compulsion, for God loves a cheerful giver."2 Corinthians 9:7
If you noticed someone attractive, you have already committed adultery in your heart. You are as guilty as if you had done it.
Looking at a woman in order to covet her. A settled intention, formed and held, not the involuntary reaction of having eyes.
The first misuse is turning Matthew 5:28 into a verdict on being human. Jesus is describing a look that is already an intention, the kind a person decides to keep having. Teaching a teenager that noticing somebody makes them an adulterer produces shame and nothing else, and shame has never once made anybody more faithful. It makes them secretive, which is the opposite of the direction this teaching runs. There is more on what the Bible says about masturbation if you want to keep going.
What Jesus is doing is closing an escape route, and the escape route belonged to men who kept the letter of the law while running a whole inner life that contradicted it. Read in context it is not a heavier burden on the scrupulous. It is a burden placed on people who thought they were fine.
The second misuse is the older one, and the church has not finished with it. The double standard that the Law carried and that Jesus dismantled has a way of reassembling itself. It shows up when a woman's clothing is discussed and a man's conduct is described as a struggle. It shows up when an affair costs a woman her place in a congregation and costs a man a season away. It shows up in every youth talk that tells girls to be careful and tells boys nothing.
That is not a modern sensitivity being imported into Scripture. It is Mark 10:11 read plainly. Jesus said a husband can commit adultery against his wife, in a legal world where that sentence did not parse, and He said it on purpose. Any church still running the old arithmetic is behind its own text by two thousand years.
And the third thing, which is not a misuse but an omission. Adultery is in the Bible because betrayal is serious, not because sex is dirty. The commandment sits between murder and theft. Something is taken from a person who trusted you, and the whole weight of the prohibition is on that.
What is new in Mark 10:11?
Under the law of the day, a married man's offence was against the other woman's husband. Saying he wrongs his own wife makes her a party with standing, which she had not been.
“I gave faithless Israel her certificate of divorce and sent her away because of all her adulteries.”
Jeremiah 3:8A whole book built on it, and the instruction in chapter 3 is to go and love her again. The image is used to describe pursuit, not to describe writing somebody off.
The most graphic chapter in Scripture on this theme, and it ends with God re-establishing the covenant. The point of the shock is the restoration that follows it.
You adulterous people, in a letter about friendship with the world. The image carries straight into the New Testament without changing its shape.
Because a rule broken is an infraction and a marriage broken is a wound. The prophets reach for the second one to say what idolatry actually costs.
Which is the strongest argument against treating this as a matter of regulation. God did not pick a legal metaphor for covenant unfaithfulness. He picked the most personal betrayal available.
However you weigh the manuscript question, the scene in John 8 is the one everybody remembers, and it is worth saying what happens at the end of it.
The accusers leave. The woman is still there. He asks whether anybody has condemned her and she says no one. Then two sentences, in this order: neither do I condemn you, and go and leave your life of sin.
Most preaching on this passage picks one of those sentences and builds the whole message on it. Take the first alone and you get a gospel with nothing to say about how anybody lives. Take the second alone and you get a church people hide from.
They were said to the same person, in that sequence, and the order is not accidental. Nobody in that story is told to clean up before the condemnation is lifted.
For related ground, see lust, fornication, sexual immorality, biblical reasons for divorce, David and Bathsheba, pornography and mercy.
Sexual unfaithfulness involving a married person, defined unevenly in the Law around household descent, levelled by Jesus when He said a husband wrongs his own wife, moved inward to a settled intention rather than an involuntary glance, and used by the prophets because betrayal of a real bond is the closest picture of what idolatry costs.
Whether it was done to you or by you, this is not a subject anybody researches from a comfortable distance. If you were betrayed, what happened was not your failure to be enough. If you were the one who did it, there is a road back and it does not begin with being told what you already know. Send it to us and somebody will sit with it and pray with you.
It is preached badly often enough that a lot of people carry a version of it that is not in the text. Send your questions in and somebody at Sound of Heaven will work through them with you.
Sexual unfaithfulness involving a married person. But the Law's definition was uneven. A married woman with any man was adultery, and a married man was in breach only if the woman was another man's wife. The offence was framed around a household's line of descent as much as around faithfulness. Jesus removes the asymmetry in Mark 10:11 and 12 by saying a man can commit adultery against his wife, which was not a category in the legal system of his day.
Exodus 20:14 and Deuteronomy 5:18 give the commandment. Leviticus 20:10 and Deuteronomy 22:22 set the penalty, which applied to both parties in the text. Numbers 5 describes a ritual for a husband who suspects his wife, with no equivalent procedure running the other way. That imbalance is in the text and it is worth seeing rather than skipping, because it explains a great deal of what Jesus does with the subject.
The Greek describes looking at a woman in order to covet her, which is a settled intention rather than an involuntary reaction. Amy Oden notes that Jesus connects the dots from outward acts to internal orientation, from murder to anger, from adultery to lust. He is not saying that noticing a person is the same as betrayal. He is saying that the thing adultery grows out of is already a matter of the heart.
No, and every good modern Bible tells you so in a footnote. John 7:53 to 8:11 is absent from the earliest Greek manuscripts of John and appears in different places in some later ones. Many scholars still regard it as a genuine memory of Jesus preserved separately. Notice also what the accusation leaves out: adultery requires two people, and only one is brought.
Because the covenant between God and Israel is described in marriage terms, so unfaithfulness to it gets marriage language. Hosea builds a whole book on it, Jeremiah 3 uses it directly, and Ezekiel 16 is the most graphic example in Scripture. James 4:4 carries the image into the New Testament. The point of the picture is not shame, it is that betrayal hurts because there was a real bond to betray.