What is forgiveness? Forgiveness is letting go of a debt that is owed without ever expecting repayment. That debt could be many things such as slander, abuse, rejection, hurts from loved ones etc..
Why forgive? If we as Christians have been forgiven for our wrong doings our debts, isn't it reasonable that we forgive without expecting repayment. We owed a debt we couldn't pay. Jesus paid our debt for us by allowing himself to be made a ransom for us and imparted unto us forgiveness.
Below Our Lord Jesus speaks to us from the Book of Matthew:
Mat 18:23 Therefore is the kingdom of heaven likened unto a certain king, which would take account of his servants.
Mat 18:24 And when he had begun to reckon, one was brought unto him, which owed him ten thousand talents.
Mat 18:25 But forasmuch as he had not to pay, his lord commanded him to be sold, and his wife, and children, and all that he had, and payment to be made.
Mat 18:26 The servant therefore fell down, and worshipped him, saying, Lord, have patience with me, and I will pay thee all.
Mat 18:27 Then the lord of that servant was moved with compassion, and loosed him, and forgave him the debt.
Mat 18:28 But the same servant went out, and found one of his fellowservants, which owed him an hundred pence: and he laid hands on him, and took him by the throat, saying, Pay me that thou owest.
Mat 18:29 And his fellowservant fell down at his feet, and besought him, saying, Have patience with me, and I will pay thee all.
Mat 18:30 And he would not: but went and cast him into prison, till he should pay the debt.
Mat 18:31 So when his fellowservants saw what was done, they were very sorry, and came and told unto their lord all that was done.
Mat 18:32 Then his lord, after that he had called him, said unto him, O thou wicked servant, I forgave thee all that debt, because thou desiredst me:
Mat 18:33 Shouldest not thou also have had compassion on thy fellowservant, even as I had pity on thee?
Mat 18:34 And his lord was wroth, and delivered him to the tormentors, till he should pay all that was due unto him.
Mat 18:35 So likewise shall my heavenly Father do also unto you, if ye from your hearts forgive not every one his brother their trespasses.