Commit Not Adultery

The shape of the practice

"Thou shalt not commit adultery" (Exodus 20:14). Deuteronomy 5:18 repeats it: "Neither shalt thou commit adultery." The commandment guards the covenant at the center of human society — the one-flesh bond of marriage: "Therefore shall a man leave his father and his mother, and shall cleave unto his wife: and they shall be one flesh" (Genesis 2:24). Scripture holds marriage in the highest honor — "Marriage is honourable in all" (Hebrews 13:4) — and ultimately treats the faithfulness of husband and wife as a living picture of Christ and His church (Ephesians 5:31-32). Adultery does not just wound two people; it defaces the picture.

Jesus moves the commandment from the act to the heart: "Ye have heard that it was said by them of old time, Thou shalt not commit adultery: But I say unto you, That whosoever looketh on a woman to lust after her hath committed adultery with her already in his heart" (Matthew 5:27-28). Faithfulness is not merely refraining from an affair; it is what your eyes linger on, what your imagination rehearses, what your heart practices when no one is watching. The commandment protects covenant love — the kind that can be trusted for a lifetime.

What it is not

• It is not only for married people. The heart-level command applies to everyone, at every age. Faithfulness in marriage is built years earlier, out of habits of the eyes and heart formed long before any wedding.
• It is not prudishness. Scripture is not embarrassed by marriage or the body; it honors both (Hebrews 13:4, 1 Corinthians 6:19-20). The commandment does not despise desire — it protects desire by keeping it inside the covenant where it blesses instead of destroys.
• It is not kept by behavior management alone. You can avoid every scandal and still cultivate a wandering heart. Jesus' point in Matthew 5 is that the standard was always interior.
• It is not the unforgivable sin. David fell here and was restored through repentance (Psalm 51). Jesus refused to condemn the woman taken in adultery, and told her, "go, and sin no more" (John 8:11). Grace is real; so is the call to walk differently.

Five practices for the week

1. Make a covenant with your eyes. Job's discipline: "I made a covenant with mine eyes" (Job 31:1). For one week, practice the deliberate second look away — from the screen, the feed, the street. Purity is mostly won in the first two seconds.
2. Clean the inputs. Audit what you watch, scroll, and listen to. Whatever trains your heart to treat people as objects, cut it off — Jesus used surgical language for exactly this (Matthew 5:29-30). The strategy scripture gives is not negotiation but flight: "Flee also youthful lusts" (2 Timothy 2:22).
3. Practice covenant-keeping in small things. Faithfulness is a muscle. Keep every small promise you make this week — showing up, following through, telling the whole truth. People who keep small covenants keep large ones.
4. Honor other people's marriages. Speak well of marriage. Refuse to be the flirtation, the secrecy, or the "harmless" attention that weakens someone else's covenant. Guard others' vows as if they were your own.
5. Walk in the light with one person. Secrecy is where this sin grows. Tell one trusted, mature believer the truth about your struggles and ask them to keep asking (James 5:16, 1 John 1:7).

Reflection prompts

• What do my eyes and my scrolling habits rehearse, and what are they training my heart to want?
• Where am I keeping a secret that thrives on staying secret?
• If I am unmarried: what habits am I building now that my future covenant will inherit?
• Do I treat the people I find attractive as whole persons made in God's image, or as material for my imagination?