I ask my classes, “Why do gangbangers ever stop at red lights?” Some students suggest that they don’t want to be caught by the police. Sure. That might motivate them sometimes. But isn’t the real reason they stop that they don’t want to be broadsided by, say, an 18-wheeler traveling 50 miles per hour? But, if that’s their motive, then the reason they stop has nothing to do with respect for the law—it is about self-interest. That they stop has nothing to do with moral goodness.
Likewise, why does the man who hates his ex-wife not murder her? We’ve already established that it is not because he cares for her: he hates her. Then why not murder? Isn’t it because of the fear of being found out and then losing his family, his friends, his reputation, his freedom, and perhaps even his life? But if he refrains from murder for selfish reasons, then isn’t he still, really, a murderer at heart? Thus the apostle John wrote in 1 Jn. 3:15, “he who hates his brother is a murderer.” John recognizes that if you hate, you are still a murderer even if you don’t actually kill. History shows, by the way, that if average people think they can get away with murder, then they will murder.
Similarly, suppose a woman and man each married to someone else start flirting with and sexually fantasizing about each other. Suppose they even realize that the object of their lust feels similarly about them. If they don’t have sex, why not? Again, isn’t it self-interest? She might get pregnant, one or both of them might get a brand-spanking-new STD, or they might get caught and thus lose their reputations and families. Perhaps the man is afraid that her husband might kill him. And so on. But if he or she refrains from actually doing it either from lack of opportunity or from fear of consequences and not because they honor God or have determined to cherish their spouse, then their refraining doesn’t make them good. That’s why Jesus said that the one who lusts commits adultery in his heart (Mat. 5:28).
Taking these verses seriously, then, are there any people who live long enough not to end up, sooner or later, being adulterous murderers? I didn’t make it out of junior high without being an adulterous murderer. Kids hated me and I hated them.
Why does the Bible teach this? It is because evil is primarily a matter of the heart. We need to connect these dots for the non-Christians who are adulterous murderers in their hearts but still believe they are good people. If we do, they might recognize their sinful condition and cry out for the grace available through Jesus’ sacrifice on the cross.
Isaiah 64:6: “All of us have become like one who is unclean, and all our righteous acts are like filthy rags; we all shrivel up like a leaf, and like the wind our sins sweep us away.”