What does the Bible say about adultery?

"You shall not commit adultery" is the seventh commandment. Adultery is the corruption of the marriage bond, and the prohibition would certainly extend to every kind of such corruption whether persons are married or not. In the New Testament, though the words, "Ye shall not" are not used, yet the evil of fornication is no less warned against (Acts 15:29; 1 Thes.4:3-4). Homosexuality is worse still -- a most flagrant corruption of the bond of marriage (Rom.1:26-27).

Let one instance suffice out of the seven occasions in that discourse when our Lord said, “I say to you.” “Ye have heard that it was said of them of old time, Thou shalt not commit adultery: but I say to you, That whosoever looks on a woman to lust after her has committed adultery with her already in his heart” (Matt. 5:27-28). Where is there the setting aside of the law? Nay, He upheld it. The law was content to forbid the actual act, the Lord went further, and not only forbad the outward act, but the inward desire.

In the Old Testament, adultery, unfaithfulness towards the spouse for the satisfaction of lust, was to be dealt with most severely. According to the law of Sinai this sin had to be punished with death (Lev. 20: 10; Deut. 22: 22-24). In the first place the law contained God's regulations for the outward and social life of His earthly people, and for this reason only the accomplished offence was to be punished, even though the tenth commandment forbad the coveting of the neighbour's wife (as well as all his possessions. Ex. 20: 17). If a Jew kept the commandment not to commit adultery, he was acting according to God's will and contributed towards the maintenance of the people's community according to God's order. Fear of the punishment threatened certainly contributed to this. However, the mere outward observance of this and all the other commandments could not justify him before God.

The tempted but godly youth says to Potiphar's wife, "Behold, my master wots not what is with me in the house, and he has committed all that he has to my hand: there is none greater in this house than I; neither has he kept back any thing from me but thee, because thou art his wife: how then can I do this great wickedness, and sin against God?" How many young men in this house tonight would have so answered? How many are convicted that they have been guilty of what Joseph calls "great wickedness"? Ah, my friends, fornication and adultery are thought little of in this world, provided it be not found out; but don't you forget that it is written, "Whoremongers and adulterers, God will judge" (Heb. 13:4). God has spoken in the plainest possible language on this point from one end of Holy Writ to the other. His final testimonies are, "But the fearful, and unbelieving, and the abominable, and murderers, and whoremongers, and sorcerers, and idolaters, and all liars, shall have their part in the lake which burns with fire and brimstone: which is the second death" (Rev. 21:8). "For without are dogs, and sorcerers, and whoremongers, and murderers, and idolaters, and whosoever loves and makes a lie" (Rev. 22:15). What a miserable set to spend eternity with in darkness and distance from God! Wretched is the man who is in this list, — happy he who is not of it!

Adultery too (a guilty infraction of the marriage bond) called for the death penalty for both the man and the woman involved in this. God does not require Gentile governments to enforce Israel's laws, but these evils are no less wicked wherever they are found. Meanwhile, God is delaying punishment, and today is commanding all people everywhere to repent (Acts 17:30). If so, they will be saved from the punishment they deserve: if not, their punishment will be not only death, but eternal torment in the lake of fire.

The penalty for incest was death for both parties (vv. 11-12). Those guilty of homosexual relations incurred the same penalty (v. 13). If a man married both a woman and her mother, all three of them were to be burned to death.

However, the Lord's answer to this is most penetrating. Moses had allowed this because of the hardness of their hearts, but from the beginning it was not so. How clearly this shows that the law itself was not at all the manifestation of God's heart! In this case law was more permissive than is the grace of God! For grace enables one to surmount difficulties in a way that law could never do.

Therefore, confirming what was implicit in creation, the Lord adds, "And I say unto you, Whosoever shall put away his wife, except it be for fornication, and shall marry another, committeth adultery: and who so marrieth her which is put away doth commit adultery." The one exception allowed here is because the marriage bond has been so violated as to be virtually broken already. If the one party is guilty of fornication, then it would not be adultery for the other party to divorce the first and marry another. But the one who married the party put away for fornication would be guilty of adultery.

The whole of Scripture is full of the errors of fornication (Acts 15 v 29) and adultery (Exodus 20 v 14). The first is sexual relationship outside of marriage and the second sexual relationship with a married person. We must clearly state that physical affection is only intended by God for one man and one woman and that within the confines of marriage and to a very limited extent by a couple committed to marriage (see previous chapter).

According to the law, adulterers were to be put to death (Lev. 20:10; Dent. 22:22; John 8:4-5). When adultery was merely suspected there was another way, involving "Bitter water that causeth the curse" (Num. 5:11-31). Yet in practice the Jews had got into the habit of putting away where adultery was not proven but only suspected (cf. Matt. 1:19). When the Pharisees and Scribes once confronted the Lord with an adulteress, He in His grace did not condemn the obviously repenting woman, but said to her, "Go, and sin no more" (John 8:11).

Here we see again that the Lord Jesus in His kingdom does not demand the literal fulfilling of the law of Sinai, but rather seeks that His own might follow Him genuinely and in a wholehearted way. For that reason He does not speak about the death penalty for the woman who had committed fornication, or more precisely, adultery. He warns His disciples about divorce and the sins caused by it. At the same time He in His grace makes room for the possible exception, that a marriage can be dissolved before God when it has been attacked in its spiritual, mental and physical unity by the terrible sin of adultery. The latter is not a commandment, but an exception by which God meets the defrauded partner in his spiritual or emotional weakness. However, it should not be forgotten that the sin of adultery can and should be forgiven if an honest confession has been made, and does not necessarily have to lead to divorce.

How serious and clear are the words of our Lord with regard to behaviour in His kingdom! The apostle Paul also writes that fornicators and adulterers will have no part in the kingdom of God (1 Cor. 6:9-10; Gal. 5:19-21; Eph. 5:5). Could it be any other way than that His revealed will is done in His kingdom? Though the world under Satan's dominion rebels against the blessed commandments of God, it should still be the deep desire of all true disciples of Jesus not only to know His will, but also to do it.

This was forbidden in the ten commandments; but neither there nor anywhere else is the sin defined. It seems clear, that as far as the man was concerned, if he had intercourse with a woman unless it was with a married woman, he would not be charged with adultery, though he himself might be married; indeed how could he be when he was allowed more wives than one, as well as concubines and slaves? If he committed adultery with a married woman or with one betrothed, both were to be put to death. Deut. 22:22-24. With the woman it was stricter, she must have no intercourse with any man but her husband. If a man was jealous of his wife there was the ordeal of the bitter waters provided to test her innocence. Num. 5:11-31. But we do not read that any man or woman was stoned for adultery, nor that any woman drank the bitter waters. We know from the New Testament that Moses had, because of the hardness of their hearts, allowed a certain looseness, and a man could divorce his wife for any cause, which was easier than bringing a suspected wife to trial. It may be that the men themselves had not good consciences, like those who brought the adulterous woman to the Lord in John 8:3. We have a dreadful picture of guiltiness in Judges 19: and Jeremiah charges Israel with being "as fed horses in the morning, every one neighed after his neighbour's wife," which loudly called for judgement. Jer. 5:8; Jer. 13:27. The Lord declared that a man morally committed adultery (or fornication) in his heart if he lusted after a woman. Adultery had also a typical meaning. Israel had been espoused to Jehovah, but instead of being a faithful wife she had sought other lovers. "With their idols have they committed adultery." Ezek. 23:37. So the false church, who has Jezebel in her midst, the Lord will cast her "and them that commit adultery with her into great tribulation, except they repent of their deeds." Rev. 2:22.

Matthew 19 carries on the subject of the spirit that is suited to the kingdom of heaven, and goes deep into the principles which govern human nature, and of what was now divinely introduced. A question asked by the Pharisees — for the Lord had drawn nigh to Judea — gives rise to the exposition of His doctrine on marriage; and turning away from the law, given on account of the hardness of their hearts, He goes back to God's institution, according to which one man and one woman were to unite together, and to be one in the sight of God. He establishes, or rather re-establishes, the true character of the indissoluble bond of marriage. I call it indissoluble, for the exception of the case of unfaithfulness, is not one; the guilty person had already broken the bond. It was no longer man and woman one flesh. At the same time, if God gave spiritual power for it, it was still better to remain unmarried.