When Jesus said in Matthew 18:22 that Peter should forgive his brother “seventy times seven” times, he was speaking from personal experience, not just handing down a golden truth. It is difficult for us to dislodge the notion that the Christ-child arrived to the planet forearmed with wisdom and perfect knowledge of the Way, to reconcile the idea that Jesus the Christ, perfect, savior-king, had to learn something as basic to holy living as obedience to God, and to do so by encountering personal difficulty, but it is so (Heb 5:8). Through Jesus, God sought also to distinguish the being of humanness from sinfulness, that is, to establish that being human is not in itself a woeful thing; on the contrary, Jesus proved that it was to this race of peculiar beings that God has affirmed his complete favor and ultimate identification.
Jesus suffered when he forgave Judas, and he had to forgive him over and over, as Judas was a thief, untrustworthy, and a false friend who Jesus knew would kill him. He suffered most because this was forgiveness without apology, without resolution, a circumstance in which most of us would feel justified in casting this friend away. This is the longsuffering God we love. Yet Jesus engaged this suffering because he saw purpose in the relationship, in his case a specific purpose relating to God's immense gift to mankind, and so he continued friendship with this man in the face of continued violation of the highest order. This is forgiveness demonstrated on a grand scale, with high stakes, yet the call to us extends also down to the mundane.
There will be more and less dramatic times for us to demonstrate this kind of forgiveness, and when we do so, we will without fail be rewarded with likeness to God, who continues to hold himself open to unworthy men, and will do so until the end of time. When the innocent forsake judgement in accordance with the will of God, immense power is released.