Bitterness is a form of anger toward God and others that brings despair of soul. It is a hatred of others and a lack of forgiveness of their wrongs, whether those wrongs are real or perceived. Our bitterness grieves that situations have not been made “right” according to our own expectations. Bitterness causes us to miss out on God’s grace in daily life, and it spreads trouble to others (Heb. 12:15). Contrary to bitterness are joy, love, and meekness.
BITTERNESS in the heart says such things as: "I want others to suffer for their wrongs against me." "I hate them." "God has done wrong to me." "I can't get over this...."