Seventh Commandment: You Shall Not Commit Adultery

What does adultery mean?

Adultery is breaking the marriage commitment by having sex with someone else.

Merriam-Webster’s Collegiate Dictionary defines adultery as “voluntary sexual intercourse between a married man and someone other than his wife or between a married woman and someone other than her husband.”

A related word found in many biblical passages is fornication.

What is fornication? Specifically the English word refers to “consensual sexual intercourse between two persons not married to each other” (Merriam-Webster’s Collegiate Dictionary). It is often used for sex before or outside of marriage.

However, the Greek word porneia, often translated fornication in the King James Version, has a broader meaning. Several times in the New King James Version it is translated “sexual immorality.”

The Seventh Commandment in principle covers all forms of sex outside of marriage. It is designed to protect marriage.

Sanctity of marriage

God intended the sexual relationship between a husband and wife to be an exclusive, intimate bond to strengthen the marriage relationship.

The creation account shows God’s wonderful intention for men and women and for the marriage bond. “And the LORD God said, ‘It is not good that man should be alone; I will make him a helper comparable to him.’ …

“And the LORD God caused a deep sleep to fall on Adam, and he slept; and He took one of his ribs, and closed up the flesh in its place. Then the rib which the LORD God had taken from man He made into a woman, and He brought her to the man.

“And Adam said: ‘This is now bone of my bones and flesh of my flesh; she shall be called Woman, because she was taken out of Man.’ Therefore a man shall leave his father and mother and be joined to his wife, and they shall become one flesh” (Genesis 2:18, 21-24).

So the prohibition of extramarital sex—adultery—was designed to protect the sanctity of marriage and show the importance of faithfulness.

The spirit of the Seventh Commandment

Jesus Christ expanded on the Seventh Commandment to show the spirit of the law. He said even looking lustfully is mental adultery: “You have heard that it was said to those of old, ‘You shall not commit adultery.’ But I say to you that whoever looks at a woman to lust for her has already committed adultery with her in his heart. If your right eye causes you to sin, pluck it out and cast it from you; for it is more profitable for you that one of your members perish, than for your whole body to be cast into hell” (Matthew 5:27-29).

Some people in the first century, as today, felt that natural appetites must be fulfilled. The apostle Paul described this approach and countered it in his first letter to the Corinthians. “Foods for the stomach and the stomach for foods [this was their argument], but God will destroy both it and them. Now the body is not for sexual immorality but for the Lord, and the Lord for the body” (1 Corinthians 6:13).

Paul explained that the God who created our bodies and who wants to live in us, wants us to be pure.

Any type of sex outside of marriage is prohibited. But God provides a way out of wrong sexual lifestyles and sins through repentance and conversion. We must flee from sexual immorality: “Flee sexual immorality. Every sin that a man does is outside the body, but he who commits sexual immorality sins against his own body” (1 Corinthians 6:18).

We must not give in to sexual lust and temptation, following the example of Joseph who fled from the advances of his master’s wife (Genesis 39:6-20).

All sex outside of marriage prohibited by the Seventh Commandment

Any type of sex outside of marriage is prohibited. The Old Testament gives many examples of wrong uses of sex: incest, homosexuality, bestiality, etc. (see Leviticus 18:6, 22-23). In principle this also includes pornography (see “Is Watching Porn Sin?”).

Paul said premarital sex, adultery, homosexuality and other sins would keep a person out of the Kingdom of God: “Do you not know that the unrighteous will not inherit the kingdom of God? Do not be deceived. Neither fornicators, nor idolaters, nor adulterers, nor homosexuals, nor sodomites, nor thieves, nor covetous, nor drunkards, nor revilers, nor extortioners will inherit the kingdom of God” (1 Corinthians 6:9-10).

But God provides a way out of wrong sexual lifestyles and sins through repentance and conversion: “And such were some of you. But you were washed, but you were sanctified, but you were justified in the name of the Lord Jesus and by the Spirit of our God” (1 Corinthians 6:11). God offers to wash away our sinful past and give us a clean, pure heart.

Sex in marriage is pure and good: “Marriage is honorable among all, and the bed undefiled; but fornicators and adulterers God will judge” (Hebrews 13:4). Don’t let society cheapen sex into a biological drive, an itch to be scratched or a hedonistic extreme sport. Read Solomon’s warnings about the lure of immorality and its consequences compared to the joy of committed love (Proverbs 5:1-20).

Solomon’s poetic conclusion is: “Let your fountain be blessed, and rejoice with the wife of your youth. As a loving deer and a graceful doe, let her breasts satisfy you at all times; and always be enraptured with her love. For why should you, my son, be enraptured by an immoral woman, and be embraced in the arms of a seductress?” (Proverbs 5:18-20).

Sexual sin

Study more about what the Bible says is sexual sin and why, as well as how to overcome it, in our article “Questions About Sex Answered From the Bible.”

See also these related resources that show how to apply the Seventh Commandment today: “Is Fantasy Harmless?” “Freedom From Addiction: Pornography” “Fighting the Works of the Flesh: Adultery” and “Fighting the Works of the Flesh: Sex Outside of Marriage.”

Spiritual adultery

God considers adultery as unfaithfulness to the marriage covenant, and so He uses it as a type of spiritual unfaithfulness. Some of the most poignant descriptions of God’s love also portray the treacherous betrayal of God’s love and faithfulness by those who turn from Him.

Ezekiel 16 is an extended analogy about God’s love for His people, and their spiritual adultery against Him and the terrible consequences.

God compared Israel to an abandoned girl He cared for and then married and cherished: “‘I swore an oath to you and entered into a covenant with you, and you became Mine,’ says the Lord GOD. …

“‘You were exceedingly beautiful, and succeeded to royalty. Your fame went out among the nations because of your beauty, for it was perfect through My splendor which I had bestowed on you,’ says the Lord GOD. ‘But you trusted in your own beauty, played the harlot because of your fame, and poured out your harlotry on everyone passing by who would have it’” (verses 8, 13-15).

Such spiritual adultery in ancient times often involved literal idols (Ezekiel 23:37), but today can involve anything that comes ahead of God in our lives, whether money, possessions, hobbies, entertainment or religious beliefs and customs not taught in the Bible.

Study more about spiritual faithfulness in our article “Called and Chosen.”