Americans were left shocked and horrified after two students entered Columbine High School in Littleton, Colorado, on April 20, 1999, and gunned down 12 of their fellow students and one teacher before turning their weapons on themselves.

It's often amazing to watch some of the gruffest, toughest people give their lives to Jesus — people from whom one would never expect to see open vulnerability. Yet, truth suddenly softens them.

Forgiveness is one of the most difficult quests in the human experience, especially when it comes to horrific crimes and injustices. Survivors of events like the Columbine tragedy – people who have made a concerted effort to let go of hate and anger toward those who perpetrated the unthinkable — offer some of the most powerful acts of forgiveness for us to ponder.