" When you indulge yourself in bitter thought, it feels so satisfying to fantasize about payback. But slowly and surely it will enlarge your capacity for self-pity, erode your ability to trust and enjoy relationships, and generally drain the happiness out of your daily life. Sin always the conscience, locks you in the prison of your own defensiveness and rationalizations, and eats you up slowly from the inside. "

― Timothy J. Keller , The Prodigal Prophet: Jonah and the Mystery of God's Mercy