What is considered adultery in the Bible?

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).

But what has become of marriage through sin! It was not the will of God that Lamech, Abraham, Jacob, Solomon and other men of the Old Testament should have several wives at the same time, and this only brought distress into their families. How serious was the adultery David committed with Bathsheba! And how are things today with regard to matrimonial morals — not only in the world, but also among Christians? In recent decades Biblical standards in society have been systematically done away with in this area too.

In God's sight immoral behaviour is so abominable that Paul had to write to Ephesus: “But fornication, and all uncleanness, or covetousness, let it not be once named among you, as becometh saints” (Eph. 5:3). This means that we should not mention these things frivolously and so make little of them. The Bible speaks very clearly as to God's judgment about these sins. Holy Scripture not only calls prostitution fornication, but all extramarital intercourse, even where there may be the intention to get married, and even if it is done only once (cf. Gen. 34 and 38). In the world today the word fornication is only used in connection with the first meaning. In the New Testament, however, extramarital intercourse in general is called fornication, that of married persons is called adultery, and both are condemned as abominable sin (Matt. 15:19; 1 Cor. 6:9; Heb. 13:4).

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.

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.

"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.

The Lord added verse 18 because the Pharisees took advantage of what the law had said, to allow divorce for virtually any cause. Deuteronomy 24:1 had required a man, if putting away his wife, to give her a bill of divorcement (Mt.19:3-9). But the Lord calls divorce and remarriage adultery (though Matthew 19:9 gives the one exception); and if one were to marry a woman divorced from her husband, he committed adultery. This is evidently a case where the first husband had not remarried, for adultery is the violation of the marriage bond. The world shows no regard for God's thoughts as to marriage and divorce, but a believer should be most careful to honor God in marriage, with the firm intention of proving consistently faithful. Then the only permission he can find for divorce in Scripture is if his spouse is guilty of fornication. If one is divorced by his spouse, then let him make sure from Scripture that his circumstances allow him to marry again.

Yet we know that throughout the Old Testament these things were ignored. Many (even believers) had more then one wife. The Pharisees too thought they could prove the Lord wrong by referring to Deut.24:1, which speaks of Moses, the lawgiver, instructing that if a man had found some uncleanness in his wife, he could give her a bill of divorcement and send her away. This bill of divorce was to guard against a man's cruel treatment of a wife by discarding her while not leaving her free to be married to any other.

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 seventh commandment safeguards the purity of human life. "Adultery" here has the widest sense, covering what are considered to be lesser forms of this sin between the sexes. The history of peoples shows those who have widely practised this evil have degraded themselves both physically and mentally, and out of it spring a host of other ills.

(V. 4). The lust of the flesh leads the Apostle to warn us against the friendship of the world, which offers every opportunity to gratify lust. The world is marked by the lust of the flesh, the lust of the eyes and the pride of life. It has manifested its enmity to God by rejecting and crucifying the Son of God. For one professing faith in the Lord Jesus to enter into friendship with the world that has crucified the Son of God is to commit spiritual adultery. “The friendship of the world is enmity with God.” Our attitude towards the world plainly declares our attitude towards God. “She that lives in pleasure is dead while she lives”, states the Apostle Paul (1 Tim. 5:6). Habits of worldly self-indulgence bring death between the soul and God. “If any man love the world, the love of the Father is not in him”, writes the Apostle John (1 John 2:15). “Whosoever therefore will be a friend of the world is the enemy of God”, says the Apostle James.

On the other hand, it is undeniable that the Jews, or Zion if you will, had the place of nearness to Jehovah which is represented under the figure of the marriage-tie, that she had been faithless and played the whore with many lovers (even the idols of the Gentiles), and that in consequence she was divorced, becoming a widow and desolate under the righteous dealing of God. Adultery was her sin, rather than fornication. No one in the least familiar with the prophets can have failed to notice this and more said of Israel. Then it was she became barren and did not bear. Praise is still silent for God in Zion; but the vow shall yet be performed to Him (Ps. 65:1); and the barren one shall sing and be no more barren but bear, astonished to find during those days of literal barrenness such an abundant offspring in the saints glorified on high, whom grace has been the while actively bringing in.