A few days ago I stumbled across an article in which a father talks about his need, as a Christian, to forgive the man who murdered his daughter. Let us not forget what an amazing thing this is; this kind of forgiveness, I firmly believe, is supernatural. There are substitutes that are merely natural, including rationalization, forgetfulness, and despair of justice, but true forgiveness goes beyond what we can naturally supply.
But.... You knew there was a "but" coming, didn't you?
But we need to bear in mind just what it is our business to forgive. We also need to remember that forgiveness doesn't undo the offense.
For example, what if I were to say, "I forgive Yigal Amir for assassinating Yitzhak Rabin," it would not show me to be exceptionally magnanimous. Everyone would notice that I am not a friend or family member of Rabin. I never met the man. Furthermore, I am not even Israeli, nor am I Jewish. If I were to presume to forgive Amir, it might reasonably be expected that I really meant there was no crime to forgive.
We can only really forgive what someone has done to us -- even in the Our Father, we pray, "Forgive us our trespasses, as we forgive those who trespass against us." The murder of Michelle Millare caused her father, Roland Millare, unimaginable grief, as well as the loss of his daughter's presence, the hope of grandchildren though her, etc. He can, by the grace of God, forgive her murderer for the pain and loss he has suffered on account of the crime, and it is a very good, even saintly, thing for him to do. In a real sense, though, he cannot forgive the harm done to others by the crime: to Michelle herself, to Michelle's mother, to any siblings, to her friends, and even to the community as a whole -- which is one reason the forgiveness of family is not enough to prevent prosecution.
The scribes and Pharisees were right to wonder, "Who can forgive sins, but God alone?"