This commandment deals with adultery only. Whereas murder violates life itself, adultery violates the most important and sacred human relationship, marriage.88God dealt with other forms of sexual sin elsewhere (cf. chs. 22-25). Adultery is the sexual union of a man and a woman when one or both of them is married to someone else. Adultery is an act, not a state, as is true of all the other prohibitions in the Ten Commandments (cf. Matt. 5:27-28).
Adultery is wrong because it disrupts the basic unit of society, namely, the husband wife relationship. God established marriage long before He gave the Mosaic Covenant. He intended it to be a permanent relationship (Gen. 2:24; Matt. 19:3-8). A new relationship based on mutual commitment comes into existence in marriage. Adultery violates that commitment and weakens the basis of the relationship. When adultery takes place the unfaithful partner temporarily abandons that commitment and future faithful commitment is uncertain. Thus the relationship is not what it was. Adultery erodes the foundation of marriage, which is faithfulness to a commitment (covenant). It does so by breaking that commitment and by establishing an intimate relationship, however temporary, with another partner (1 Cor. 6:16). It also incurs God's judgment. Under the Old Covenant the Israelites dealt with adulteresses more severely than adulterers. Under the New Covenant we should not execute adulteresses or adulterers. God has promised that He will deal with both (Heb. 13:4; cf. 1 Cor. 6:9-10). Adultery does not terminate a marriage in God's sight much less one's salvation. However it might eventually result in the termination of a marriage through divorce and remarriage.
How should a Christian respond to a spouse who has committed adultery? He or she should forgive the unfaithful mate (John 8:1-11). How often should we do this? How often has God forgiven you for being unfaithful to Him (cf. Matt. 18:21-35)? Remember God's instructions to Hosea concerning his unfaithful wife and how God used Hosea's situation as an illustration of His own love for Israel (cf. Ezek. 23:37; James 4:4; Deut. 5:5). Does not forgiveness encourage infidelity? Perhaps, but godly love forgives. God allows us to abuse His mercy, but appreciation for His love and grace will result in our wanting to remain faithful to Him. We should deal with one another as God deals with us, namely, graciously (John 13:34). If a spouse continues to be unfaithful it may become wise or necessary to separate (action), but there must be continuing forgiveness (attitude).
How can we guard against committing adultery ourselves? First, Scripture stresses the importance of guarding our own hearts, the seat of our affections (Matt. 15:19; Prov. 4:23; 7:25). Second, we should realize that God has a claim on our bodies as well as our souls (1 Cor. 6:13-20). Third, we should cultivate our relationship with our spouses (1 Cor. 7:1-5). The husband wife relationship is more fundamental than the parent child relationship. Husbands need to take the initiative in cultivating this relationship (Eph. 5:25-31).
