The Bible teaches us to always forgive those who offend us. Forgiveness is one of the basic doctrines of the church of God. Jesus taught us that the way we deal with those who sin against us is the same way that our heavenly Father will deal with us. If we forgive those who offend us, our heavenly Father will also forgive us. But if we refuse to forgive those who sin against us, our heavenly Father will not forgive us.
The heart who forgives should forget about the offense. God forgives us and forgets our iniquities. He said that our transgressions will he not remember anymore. So, if God whose memory is bigger than that of any of us can forget the offenses of the person He has forgiven, we too should learn to forget the evil that others do to us.
We should learn to work in love. When we work in love, we will be able to forgive those who have offended us. Love can easily forget what evil people have done to it.