The Seventh of the Ten Commandments reads, “You shall not commit adultery” (Exodus 20:14). The Commandment does not define or qualify what adultery is; nor does it prescribe a penalty for the offence. Elsewhere within the Law of Moses, however, we find both a definition for adultery and the penalty:
“If a man commits adultery with the wife of his neighbor, both the adulterer and the adulteress shall surely be put to death.” (Leviticus 20:10)
In the Book of Deuteronomy the definition of adultery is extended to include sexual intercourse between a man and another man’s fiancée (Deuteronomy 22:22-24), which was likewise a capital offence.
Some have claimed that the term ‘adultery’ in the Seventh Commandment refers collectively to all forms of sexual sin. However, this is not strictly correct. The Hebrew word na’aph used here refers to the breaking of wedlock by having sexual intercourse with the wife or fiancée of another man. The law did not even explicitly cover the case where a married man cheats on his wife with an unmarried woman.
This is by no means to say that other forms of sexual behaviour were permitted under the Law of Moses. Leviticus 18 and 20 prohibit a number of other types of sexual act, including homosexual sex, bestiality, various forms of incest, and sexual intercourse with a menstrual woman. All of these were punishable by death except the last (which was punishable by exile).
Premarital sex is dealt with elsewhere in the Law of Moses. Exodus 22:16-17 states that if a man seduced a virgin who was not engaged, he had to pay the bride-price for the woman and marry her. If her father refused to let him marry her, he had to pay the bride-price anyway. Deuteronomy 22:13-21 further prescribes capital punishment for a woman who was not a virgin at the time of marriage if her husband chose to formally complain.
The Law of Moses had strict and detailed statutes regarding sexual behaviour; however the Seventh Commandment concerned only one specific aspect, namely sexual intercourse of an engaged or married woman with someone other than her husband/fiancé.
Having clarified the meaning of the commandment, we must ask how to apply it today. As with previous commandments, the key is to be found in the teachings of the Lord Jesus Christ. In Jesus’ day, the Jewish religious leaders had established loopholes that were not fair to women. A man could divorce his wife for any reason (Matthew 19:3) and take another wife. The bonds of marriage could be easily broken and reformed to prevent adultery from occurring by the letter of the Law.
Jesus’ teachings brought out the spirit of the adultery law:
“27 "You have heard that it was said, 'You shall not commit adultery.' 28 But I say to you that everyone who looks at a woman with lustful intent has already committed adultery with her in his heart. 31 "It was also said, 'Whoever divorces his wife, let him give her a certificate of divorce.' 32 But I say to you that everyone who divorces his wife, except on the ground of sexual immorality, makes her commit adultery, and whoever marries a divorced woman commits adultery.” (Matthew 5:27-28,31-32)
As we saw with the commandment against murder, one need not commit the physical act in order to bear the full guilt of the offence. The desire to commit the act is enough. Furthermore, to divorce a faithful wife in order to take another, or to marry another man’s wife who had been so discarded, is adultery in Jesus’ eyes. There are no loopholes with Jesus; he sees straight to the heart of the matter.
Jesus also made it clear that there was no double standard between men and women. For a man to sleep with a woman other than his wife was just as much adultery as it was for a woman to sleep with a man other than her husband (Mark 10:11-12). Both husband and wife are to honour the sanctity of marriage (Hebrews 13:4).
Jesus’ judgment of a situation where a woman was caught in adultery showed his mercy and wisdom (John 8:3-11). He had mercy on the woman, preventing her from being stoned to death although this was the punishment called for under the law. He saved her from being another victim of the gendered double standard: she had been “caught in the act of adultery” (John 8:4), which means a male must also have been present; yet no male had been apprehended.
Jesus’ mercy on this woman showed that there is hope for those who get involved in sexual sin such as adultery. However, it is still a very serious sin. We in the Western world have forgotten how serious it is, because it is no longer a crime in most Western countries (unlike “Thou shalt not kill,” “Thou shalt not steal” and “Thou shalt not bear false witness”). Yet adultery can irreparably damage relationships and destroy families.
“Do not be deceived,” wrote the Apostle Paul, before mentioning “adulterers” among the unrighteous who, apart from the cleansing that God offers through Jesus Christ, cannot inherit the kingdom of God (1 Corinthians 6:9).