When we begin to live a christian life we begin to live a life of the spirit. This means taking up the nature of the spirit and putting away the manifestations of the flesh. One of the things the spirit helps us to do is to be able to forgive. Forgiveness is a difficult task for the flesh especially in certain situations.
But we know that obeying the leading of the flesh would not do us any good. Some people may view forgiveness as a form of weakness. Most people may often believe that retaliation proves that you're a tough person. But according to the christian faith that paradigm is wrong. If forgiveness can't be found in our hearts then something is wrong somewhere.
If that was the case then we shouldn't expect to be forgiven by God because we don't deserve it. God is so merciful towards us that the things we do which are evil now seems to be okay to do because God withholds his anger from coming upon us. God forgives us even when we don't ask.
If God should treat us that way then we don't have any reason to deny people of forgiveness when they ask for it. We should be a representation of Jesus here on earth by the way we treat others
We should learn to forgive, just as Our father in heaven forgives us