“Do not take revenge nor bear a grudge” is a commandment written in the Torah (Lev. 19:17).
If one is able to realize that he and the person who offended him are both part of a greater whole, taking revenge becomes absurd. I would be like punishing your right hand when it hits your left thumb with a hammer. Maimonides considers the desire for revenge one of the most negative of character traits, the result of attributing too much importance to matters which, in reality, are trivial.
The intent of this approach is not to excuse the perpetrator of an evil act, but to have the victim focus on productive reflection rather than destructive thoughts of vengeance.