Let us suppose that a Christian commits a sin. He tells a lie, for instance. Now when he tells this lie, does he feel guilty or does he feel bitter? The answer is guilty. When we sin, we feel guilty. It is straightforward. Now let us suppose that someone told a lie about this same Christian and spread it all over town. What does he feel now—guilt or bitterness? Guilt is what we feel when we sin, and bitterness is what we feel when others sin against us. The very definition of bitterness points to