Forgiveness is one of the commandments of God for us. We are to always forgive one another. The attributes of God which we are to exhibit is forgiveness. Every christian should learn to forgive those who offend him. It is the teachings of Jesus Christ which we must obey. We should not keep offenses. We should be forgiving.
Forgiveness should not be conditional. We should forgive out of love, we should forgive without any condition. The Lord Jesus Christ said we should forgive those who offend us as much as 70×7 times. That is a whole lot. We should forgive without reservation. Is it possible that one person could offend only you 490 times? That is not real. That means that we must always forgive. There is no condition in which we will not forgive.
As christians, we should be careful not to sin. The Bible says we should sin not. We should not commit sin, we should run away from every sin. If we sin unintentionally, God will forgive us when we confess our sin. We should not sin willfully. Also, we should avoid those sins which is referred to as unpardonable.