Resentment will Kill you. Lots of research shows it causes ulcers and physical problems. There is only one cure for resentment: Forgiveness. Resentment is not Righteous Indignation, which is moral outrage at injustice. Resentment comes from feeling demeaned and believing your worth has been lessened. So the real problem with resentment is doubts in your own mind about your worth, not the other person out there. Resentment is a problem you have with yourself.