Hating Your Brother In Your Heart

The Torah urges us that if we harbor some resentment against a fellow Jew not to bottle it up in one's heart. One has to come out with one's feelings into the open, speaking them, and rebuking the person who one thinks as guilty of having bad-mouthed him or otherwise hurt him to cause such hatred. Do not assume in your heart that whatever it is the other Jew has done to cause you to hate him he has done purposely and that he continues to feel hostile towards you. Give him the benefit of the doubt and discuss the matter with him. The discussion could lead to one of two possible results. He may explain to you that he had good reason for what he did so that there is no reason to hate him. Or, he may change his attitude towards you, undertaking not to continue hostile conduct. As a result he becomes "your friend, your brother".

(Ohr HaChaim)