Forgive Us Our Debts,
As We Also Have Forgiven Our Debtors.

This is an extremely dangerous prayer to pray, but it contains a principle that the New Testament takes very seriously. The supreme warning from Jesus is that God will judge us according to how we have judged other people. Since man is saved by grace, what better evidence could there be of a man's salvation than that he offers others the grace he himself has received? If such grace is not conspicuous in our lives, we may validly question the genuineness of our own alleged conversion. We must take God seriously at this point. ... It is an insult to God for us to withhold forgiveness and grace to those who ask us, while claiming to be forgiven and saved by grace ourselves.

There is another important point to consider here. Even in our act of forgiveness there is no merit. We cannot commend ourselves to God and claim forgiveness merely cause we have shown forgiveness to someone else. Our forgiveness in no way obligates God toward us. ... We are unworthy servants; we have only done what was our duty.

The bottom line of what Jesus is saying is this: "Forgiven people forgive other people".

- Excerpt from Does Prayer Change Things - by R.C. Sproul.