1: It causes bitterness and sorrow.
2: It hinders your blessings from God.
3: It causes ulcer and high blood pressure.
4: It brings about disunity and misunderstanding.
5: It causes grieve.
6: It brings about separation and division.
7: It brings rejection hatred and wickedness.
8: It weakens your prayer power.
9: It causes jealousy and envy which a sin unto God.
10: Forgiveness is a command from God. So, if we do not you are disobedient.
11: Unforgiveness takes away peace and joy.
12: It makes the offended miserable.
13: Satan uses it to weaken and destroy and to hinder our fellowship with God.
14: Unforgiveness gives Satan authority and power over the offended