There's a series of essays at the WaPo on the subject of forgiveness. The debate centers around whether or not it is right to forgive our enemies, even when they commit atrocities against us.
In reflection, I think this debate misses the point. Forgiveness--and it's opposite, wrath--are two very different human emotional responses. Wrath stems from our most basic instinct: fear. We are made afraid by the actions of those who have harmed us, and we fear that they will harm us again unless they are caught and punished. And we also hope that the punishment will strike a sufficient fear in our enemies so that they do not attack us again.
Forgiveness, on the other hand, is a conscious decision to let go of wrath once our enemies cannot hurt us any longer. This is a challenge for we humans. I remember when Timoth McVeigh was being tried and the question was: life in prison, or death penalty? Nearly every family member of the victims emotionally pleaded for McVeigh to die, saying that they could not find 'closure' until they knew he was dead. Interviewed years later, these same people admitted that they had not found closure despite his execution.
These people are still afraid of McVeigh, even though he is dead. To say that his offense is 'unforgivable' is in essence agreeing to live in fear of McVeigh for all eternity. Some may say this is the righteous path, but what kind of life is it to live perpetually in fear?
But my point here is that forgiveness is a choice. To withhold forgiveness is an instinct. The latter is quite easy, while the former is extremely hard and pits us against our basic human nature.
And maybe that's not such a bad thing.