Unconditional Forgiveness

I used to feel resentment whenever I am mistreated and unfair by someone, and my honesty is suspected, while I seem to be relatively patient in any physical violence. However, if I were a true Christian, how would I do in such a situation? As I was delivered out of sins by Jesus Christ without any cost, it is natural that I should also forgive anyone who slanders me. Forgiveness as well as thanks and joy should be unconditional for all Christians. As Jesus prayed for Pharisees who scoffed at him and crucified him, the prayer for foes should also be unconditional for all Christians.