Supreme Court Justice Potter Stewart gave us a memorable quote about pornography. He couldn't define it, he said in 1964, "but I know it when I see it."

In an entirely different realm, I feel the same way about grace. It's impossible to explain grace, (although the Catechism of the Catholic Church gives a try), but we know it when we experience it.

Americans experienced grace this past June. When nine South Carolinians were gunned down at a Bible study grace was made manifest in the forgiveness offered to the killer by the victims' families.

College student Chris Singleton said he forgave Dylann Roof, his mother's alleged killer, just a day after Sharonda Coleman-Singleton was fatally shot. Families of the others murdered at Emanuel African Methodist Episcopal Church followed suit, saying they would pray for Roof.

What could explain this generosity besides grace? Roof later made the heartbreaking comment that he almost didn't follow through with the killings because everyone at the Bible study group was so nice to him.

In 2006, we saw a similar outpouring of grace when 10 girls were murdered in an Amish school in Pennsylvania, and the Amish community found it in their hearts to forgive.

Not coincidentally, both tragedies occurred within strong faith communities. It's certainly possible for a single person to forgive, but how much more does the grace of community sustain and inspire us as we forgive? It's a lesson for our society. We need each other. Faith lives in community and is often where grace manifests.

Forgiveness isn't easy. I struggle with forgiveness. In light of the South Carolina killings, I'm embarrassed to think of the petty things I fail to forgive. I can conjure up old injustices from years back and let them poison an otherwise beautiful day. I can seethe about the person who cuts into line ahead of me, or dwell on an insult.

Forgiveness isn't a magic bullet to make hurt and anger disappear, but the grace that brings forgiveness offers us a way toward healing.

In my work for death penalty repeal, I meet people who have grappled with forgiving large hurts.

For some, Jesus -- who looked down from the brutality and pain of the cross and asked God to forgive his tormentors -- is the model to follow. That act of love bestowed grace not only on his executioners but provided Jesus himself with release and consolation.

In the wake of the massacre in Charleston, the Rev. Jonathan Newton, an AME pastor in Washington, said anger is a natural response.

"It makes some of us want to explode," he told The Associated Press. But forgiveness "is not about that person, it's about you. In order for you to be free, you've got to let it out."

We pray for grace as we struggle to forgive. Writer Anne Lamott says this about grace: "I do not at all understand the mystery of grace -- only that it meets us where we are and does not leave us where it found us."

Effie Caldarola is a columnist with the Catholic News Service.



- Effie Caldarola is a columnist with the Catholic News Service.