Peter went up to Jesus and said, ‘Lord, how often must I forgive my brother if he wrongs me? As often as seven times?’ Jesus answered, ‘Not seven, I tell you, but seventy-seven times.
‘And so the kingdom of heaven may be compared to a king who decided to settle his accounts with his servants. When the reckoning began, they brought him a man who owed ten thousand talents; but he had no means of paying, so his master gave orders that he should be sold, together with his wife and children and all his possessions, to meet the debt. At this, the servant threw himself down at his master’s feet. “Give me time” he said “and I will pay the whole sum.” And the servant’s master felt so sorry for him that he let him go and cancelled the debt. Now as this servant went out, he happened to meet a fellow servant who owed him one hundred denarii; and he seized him by the throat and began to throttle him. “Pay what you owe me” he said. His fellow servant fell at his feet and implored him, saying, “Give me time and I will pay you.” But the other would not agree; on the contrary, he had him thrown into prison till he should pay the debt. His fellow servants were deeply distressed when they saw what had happened, and they went to their master and reported the whole affair to him. Then the master sent for him. “You wicked servant,” he said “I cancelled all that debt of yours when you appealed to me. Were you not bound, then, to have pity on your fellow servant just as I had pity on you?” And in his anger the master handed him over to the torturers till he should pay all his debt. And that is how my heavenly Father will deal with you unless you each forgive your brother from your heart.’
Jesus had now finished what he wanted to say, and he left Galilee and came into the part of Judaea which is on the far side of the Jordan.
Source: Jerusalem Bible
Catechism of the Catholic Church
And forgive us our trespasses . . .
2839 With bold confidence, we began praying to our Father. In begging him that his name be hallowed, we were in fact asking him that we ourselves might be always made more holy. But though we are clothed with the baptismal garment, we do not cease to sin, to turn away from God. Now, in this new petition, we return to him like the prodigal son and, like the tax collector, recognize that we are sinners before him. Our petition begins with a “confession” of our wretchedness and his mercy. Our hope is firm because, in his Son, “we have redemption, the forgiveness of sins.” We find the efficacious and undoubted sign of his forgiveness in the sacraments of his Church.
2840 Now – and this is daunting – this outpouring of mercy cannot penetrate our hearts as long as we have not forgiven those who have trespassed against us. Love, like the Body of Christ, is indivisible; we cannot love the God we cannot see if we do not love the brother or sister we do see. In refusing to forgive our brothers and sisters, our hearts are closed and their hardness makes them impervious to the Father’s merciful love; but in confessing our sins, our hearts are opened to his grace.
2841 This petition is so important that it is the only one to which the Lord returns and which he develops explicitly in the Sermon on the Mount. This crucial requirement of the covenant mystery is impossible for man. But “with God all things are possible.”
. . . as we forgive those who trespass against us
2842 This “as” is not unique in Jesus’ teaching: “You, therefore, must be perfect, as your heavenly Father is perfect”; “Be merciful, even as your Father is merciful”; “A new commandment I give to you, that you love one another, even as I have loved you, that you also love one another.” It is impossible to keep the Lord’s commandment by imitating the divine model from outside; there has to be a vital participation, coming from the depths of the heart, in the holiness and the mercy and the love of our God. Only the Spirit by whom we live can make “ours” the same mind that was in Christ Jesus. Then the unity of forgiveness becomes possible and we find ourselves “forgiving one another, as God in Christ forgave” us.
2843 Thus the Lord’s words on forgiveness, the love that loves to the end, become a living reality. The parable of the merciless servant, which crowns the Lord’s teaching on ecclesial communion, ends with these words: “So also my heavenly Father will do to every one of you, if you do not forgive your brother from your heart.” It is there, in fact, “in the depths of the heart,” that everything is bound and loosed. It is not in our power not to feel or to forget an offense; but the heart that offers itself to the Holy Spirit turns injury into compassion and purifies the memory in transforming the hurt into intercession.
2844 Christian prayer extends to the forgiveness of enemies, transfiguring the disciple by configuring him to his Master. Forgiveness is a high-point of Christian prayer; only hearts attuned to God’s compassion can receive the gift of prayer. Forgiveness also bears witness that, in our world, love is stronger than sin. The martyrs of yesterday and today bear this witness to Jesus. Forgiveness is the fundamental condition of the reconciliation of the children of God with their Father and of men with one another.
2845 There is no limit or measure to this essentially divine forgiveness, whether one speaks of “sins” as in Luke (11:4), “debts” as in Matthew (6:12). We are always debtors: “Owe no one anything, except to love one another.” The communion of the Holy Trinity is the source and criterion of truth in every relationship. It is lived out in prayer, above all in the Eucharist.
God does not accept the sacrifice of a sower of disunion, but commands that he depart from the altar so that he may first be reconciled with his brother. For God can be appeased only by prayers that make peace. To God, the better offering is peace, brotherly concord, and a people made one in the unity of the Father, Son, and Holy Spirit.