I want to share something which i saw a while back. (:
If someone does a bad deed onto you, and you make du’a that something bad will happen to him, then it is unlikely that anything will happen to him because the situation is one all; He did something bad to you and you did something bad (du’a bad things) to him as well.
But if you forgive him in all sincerity but yet again he does something bad to you, then the situation is one-nil. If he is a worshipping Muslim, his good deeds will go to you, and if he is not a worshipping Muslim, Allah will rightfully repay him for what he has done for He is Most Fair.
– Shared by my Ustaz. InsyaAllah may we learn to forgive, forgive and forgive.
(credits to *fingularity)