Why Forgive?
The Greatest Secret of Forgiveness.
Our Blessed Lord assures that the only way to be forgiven of our sins is when we forgive others (there’s no alternative to this – read carefully):
“For if you forgive other people when they sin against you, your heavenly Father will also forgive you. But if you do not forgive others their sins, your Father will not forgive your sins.” – Lord Jesus Christ (Matthew 6:14 – 15)
P/S:
The answer to the question: (why are we not forgiven?) is “because you didn’t forgive others”.
Thus it’s highly probable that based on the “degree we forgive others”, that’s how much “forgiveness we may receive” equivalently (a reasonable thought though not written like this in Holy Scripture – God has the final say on any principle).