″You conservatives are homophobic! The Bible says so much about heterosexual sin and so little about homosexual sin, but you ignore the former and focus entirely on the latter.″ There is some truth to this rebuke. Though heterosexual sin is so prevalent today, we seem to be reluctant to talk about its evils.

The Bible takes sexual sin very seriously. This includes, but is not limited to, adultery-sexual relations in which at least one person is married. Forbidden in the Ten Commandments (Deuteronomy 5:18), adultery was punishable by death in the Old Testament (Deuteronomy 22:22-25). Elsewhere, the Bible not only considers it a sin against one's spouse, but also regards it as a sin against God (Genesis 39:9; 2 Samuel 12:10; Psalm 51:4). In the New Testament, Paul makes it clear that unrepentant adulterers will not enter the kingdom of God (1 Corinthians 6:9-10). God's abhorrence of adultery should act as a deterrent to it even today.

Adultery is especially serious because the marriage tie mirrors the tie between God and His people. It has to do with that all-important aspect of human life: binding commitment to God and to spouse. Paul explains that adultery is serious because our bodies are a part of the body of Christ (vv. 13-20). But if one commits adultery, the body belonging to Christ becomes one with someone in a way that violates its oneness with Christ.

The damaging consequences adultery has on various parties also explains why God despises this sin. While He forgives those who are genuinely repentant, forgiveness does not erase the painful consequences of sin. The betrayed spouse may be hurt beyond reconciliation, their children may have to suffer the consequences of a broken home, and the other person involved in the adulterous act may also be deeply broken. I know of a church leader who committed adultery with a young woman. Following genuine repentance, he was restored to his wife and later to his ministry. He found out many years later that the girl whom he committed adultery with had become a prostitute, and his sin had most likely led her down this path.

Jesus went to the root cause of adultery when He said, ″Anyone who looks at a woman lustfully has already committed adultery with her in his heart″ (Matthew 5:28). To lust after someone is to desire to have sexual relations with them, believing that sex with them would satisfy a void in our heart. By entertaining lustful thoughts, we open the door to the more serious sin of physical adultery. Paul's counsel to Timothy to ″flee the evil desires of youth″ (2 Timothy 2:22) is as relevant today as it was in Paul's day.