Just before the 9/11 terrorists murdered my nephew (a passenger on the first plane to strike the World Trade Center) and almost 3,000 other people, I read Catholic writer Antoinette Bosco's book, Choosing Mercy: A Mother of Murder Victims Pleads to End the Death Penalty .
The title tells you enough to know that Toni Bosco had a difficult journey toward forgiveness and, finally, reconciliation, a condition that does not always accompany forgiveness.
In the ensuing dozen years, I've found the idea of forgiveness increasingly complex. Forgiveness can be risky. It can be painful. Yes, it can be and usually is necessary, but if you imagine it's an easy matter, you are delusional.
In my own 9/11 case, there were no hijackers left alive to forgive in person even if I wanted to. All of them obviously perished with the people they killed. So in such a case, what might forgiveness look like? And what might it mean?
A friend who also is an elder at my church and who has run some classes he calls "The Forgiveness Café" will join me over the April 26-28 weekend to lead a discussion of exactly these kinds of questions about forgiveness. We'll be offering this forgiveness seminar  at Kirkridge Retreat Center in Pennsylvania, a place of Christian foundation that welcomes everyone, including many Catholics who have been both seminar leaders and participants.
Not all of us have to think about forgiving murderers of people we love, as Toni Bosco and I do. But each of us has been wounded in countless ways, and each of us has wounded others. We've gossiped about each other, insulted one another, failed to treat each other with respect. And that's just on the personal level.
What about the broader picture? Can we forgive our government for what we believe were immoral actions? Can we forgive our churches for the ways they've failed to be the trustworthy instruments of God?
And perhaps even more difficult is the question of whether we ourselves are willing to be forgiven or even to acknowledge that we need to receive forgiveness. Such an acknowledgement concedes that we are less than honest, less than trustworthy. Can we accept such hard truths about ourselves?
And are we able to grasp the reality that sometimes what seems to be forgiveness may be something else, something less, something self-centered?
One of the cases we'll talk about at our April seminar is the 2006 shooting  of Amish children at West Nickel Mines School in Pennsylvania. The Amish families immediately said they forgave the shooter, who committed suicide. And that action gained lots of public admiration as well as disbelief.
But those who admired it often seemed unaware that the Amish believed their own eternal salvation would be in danger if they did not offer such forgiveness. So given that reality, was the forgiveness real or was it an act of self-protection?
And is forgiveness in some sense always an act of self-protection in that it can and should unburden us, freeing us to live without the kind of self-destructive anger that sometimes can do as much damage as the original abuse, insult, injury or dishonesty?
Christians, of course, find forgiveness advocated in various passages of scripture. Beyond that, they have the painful example of Jesus in his very passion on the cross asking God to forgive the people who nailed him there.
But is Jesus our model here? Or is his forgiveness of his killers just one more way in which we ourselves cannot be Jesus?
See how simple the matter of forgiveness is? Me neither, which is why I need the experiences of others to inform and guide me. In other words, I teach to learn.
If, like me, you've struggled with forgiveness, perhaps you'd join us at Kirkridge to see if together we might move toward answers that make sense for our lives.
[Bill Tammeus, a Presbyterian elder and former award-winning Faith columnist for The Kansas City Star, writes the daily "Faith Matters" blog  for the Star's website and a monthly column for The Presbyterian Outlook. His latest book, co-authored with Rabbi Jacques Cukierkorn, is They Were Just People: Stories of Rescue in Poland During the Holocaust . Email him at firstname.lastname@example.org .]
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