Tyndale Open Bible Dictionary

ADULTERY

A breach of the unity of marriage. It describes any act of sexual intercourse between a married woman and a man other than her husband, and all sexual intercourse involving a married man and a woman other than his wife.

In OT times, polygamous unions were not considered adulterous (cf. Dt 21:15). Nor was a husband branded as an adulterer if he had intercourse with a slave woman (Gn 16:1-4; 30:1-5) or a prostitute (Gn 38:15-18)—though the latter was, of course, condemned as immoral (1 Cor 6:15).

Any imbalance between the sexes was dispelled by Jesus in his teaching on divorce and remarriage. While he did not rule out the possibility of divorce in cases of sexual unfaithfulness (Mt 5:32; 19:9), he warned that in all other circumstances remarriage involves both (ex-)husband and (ex-)wife in adultery. Paul added that the charge of adultery only applies if the remarried person’s original partner is still alive (Rom 7:2-3).

Jesus also sharpened the OT’s definition of adultery by applying it to a man’s thought life. Any man who fantasizes in lust (as distinct from just being tempted) has committed adultery in mind and intention, even though there is no physical contact (Mt 5:27-28; cf. Jb 31:1, 9).

The Bible’s condemnation of adultery is written into the heart of the OT law, prophecy, and wisdom literature. The Ten Commandments ban it unequivocally (Ex 20:14; Dt 5:18). The prophets list it among offenses that attract God’s anger and judgment (Jer 23:11-14; Ez 22:11; Mal 3:5). And the book of Proverbs scorns it as a senseless act by which a man destroys himself (Prv 6:23-35; cf. 7:6-27).

The NT echoes that clear condemnation. Where there is no repentance, adultery excludes those who practice it from God’s kingdom (1 Cor 6:9). It is the very opposite of love of one’s neighbor (Rom 13:9-10), and it stands under the judgment of God himself (Heb 13:4).

In the OT the penalty for adultery is death—for both the man and the woman (Lv 20:10; Dt 22:22). The same applies if the woman is single but engaged to another man, assuming she has not been raped (in which case only the man is to be executed—Dt 22:23-27). The refrain “You will cleanse the land from evil” (22:24) shows that adultery was considered a serious threat to society’s health, not simply an attack on the family lives of the two people involved.

With such serious consequences, it was important to establish guilt beyond doubt. In cases of serious suspicion but insufficient evidence, the wife concerned was put through an elaborate ritual test that included taking an oath and drinking bitter water. The result was not a matter of chance because she stood in the Lord’s presence (Nm 5:11-31).

In both the OT and NT, the language of adultery is used figuratively to describe human unfaithfulness to God. The OT prophets likened God’s covenant relationship with his people to marriage (Is 54:5-8; cf. Rv 21:2), so in their eyes the breaking of that relationship, especially by idolatry, was equivalent to spiritual adultery (Jer 5:7-8; 13:22-27; Ez 23:37).

Jesus used the same imagery to characterize those who either rejected his claims or showed their lack of faith in him by demanding unnecessary extra signs of his deity (Mt 12:39; 16:4; Mk 8:38). And in another vivid NT passage, James describes God as a loving, jealous husband coming to deal with his adulterous people who have become good friends with the world and its false standards (Jas 4:4).

This is the special theme of the prophet Hosea. God used the prophet’s own experience of a marriage broken by adultery to teach the seriousness of his people’s unfaithfulness to him (Hos 2:2-6) and his keen longing for a full reconciliation (3:1-5). Spiritual infidelity, like physical adultery, brings God’s judgment. But in both cases his overwhelming desire is for a mended relationship following sincere repentance (Jer 3:1-14; Ez 16:1-63).