Forgive us our trespasses as we forgive those who trespass against us
The mercy of God is beyond description. While he is offering us a model prayer he is teaching us a way of life whereby we can be pleasing in his sight.
But that is not all. In this same prayer he gives us an easy method for attracting an indulgent and merciful judgment on our lives. He gives us the possibility of ourselves mitigating the sentence hanging over us and of compelling him to pardon us. What else could he do in the face of our generosity when we ask him to forgive us as we have forgiven our neighbor?
If we are faithful in this prayer, each of us will ask forgiveness for our own failings after we have forgiven the sins of those who have sinned against us. I mean those who have sinned against us, not only those who have sinned against our Master.
There is, in fact, in some of us a very bad habit. We treat our sins
against God, however appalling, with gentle indulgence: but when by contrast
it is a matter of sins against us ourselves, albeit very tiny ones, we
exact reparation with ruthless severity.
Anyone who has not forgiven from the bottom of the heart the brother
or sister who has done him wrong will only obtain from this prayer his
own condemnation, rather than any mercy. It will be his own action that
draws a much more severe judgment on himself, seeing that in effect by these words we are asking God to behave as we have behaved ourselves.