It is in first discovering the value of forgiving that makes forgiving others more desirable. Forgive, and we shall be forgiven Luke_6:37, if that was our only reason then we would be as those that give just to receive. It is in knowing it is for our healing that we forgive others, and not just to obtain forgiveness.
To forgive is to set a prisoner free, and then to discover that prisoner was you.
Forgiveness and repentance run hand in hand, as we see with the woman that anointed Jesus’ feet, how she being forgiven of so much caused her to love more. Luke 7:47
But without the law/rules how would we know just how much we sin. Romans 7:9 Jesus said if you were blind you would have no sins, if one does not know it is wrong then how can it be counted unto them as sin? Joh_9:41How could it cause a need to repent without knowing an error was made?
It is in our spiritual growth we learn the law/rules, the commandments which allow the Holy Spirit to convict us of when we break them. This leads us to need to repent to remove the guilt which comes from the feeling of conviction. Joh_16:8
The more we grow the more we are able to be convicted of, causing the need to repent, feeling that forgiveness allows us to experience the love of God which allows us to be able to show that love to others, through our forgiving of them. As we show love to others our healing grows.
How can we give, what we do not have, the more we have of the feeling of forgiveness the more we are able to give it to others, with a desire to do so.