"There is no greater expression of love than this: to lay down your life for a friend. And you are my friends." So said Jesus of Nazareth the night before he gave up his life for humanity.

It has been a month since Cassie Bernall returned the favor.

Cassie was one of 13 people killed by Eric Harris and Dylan Klebold as they rampaged through Columbine High School in Littleton, Colorado.

By all accounts, it had been a typical Tuesday for this not-so-typical 17-year-old--until Cassie heard the gunshots and the screams, until Cassie's killers blasted into the library and offered her a choice between life and death.

Asked by the teenage terrorists if she believed in God, Cassie calmly and emphatically answered, "Yes." Then they executed her.

Some say Cassie’s answer sealed her fate, but they're wrong. Cassie’s fate was sealed a few years earlier, the first time she answered "yes" to the question of her faith in God. I don’t know where or when it happened--at church, at home, at youth group--but I know how it happened: There was a moment when God called Cassie and asked her if she believed--a moment He had set aside just for her. And she said, "Yes."

She probably didn’t know how profoundly that answer would change her life. For Cassie, saying yes to God wasn’t a Sunday sermon catchphrase. It would remake her, define her, change her destiny, and perhaps even immortalize her name.

Cassie’s answer was drowned out by the spray of bullets, but only briefly. When the gentle, piercing words of Cassie Bernall’s faith shot back at her would-be executioners, the killers weren’t the only ones to hear them. Her classmates heard them, and they would share her story with us. Just hours after the siege, the story of Cassie's death ricocheted across Colorado, and now it echoes across a nation.

Cassie had written streams of letters to friends and family, and as news of her death spread, so too did her inspiring words. A friend who survived the assault shared a letter Cassie had written on the very night before she was murdered. It closed with a simple but sweeping statement of faith: "I want to live completely for God." Like her savior, Cassie put her words into action.

But don’t let Cassie's public confession and heroic martyrdom give you the wrong impression. Cassie had not lived the life of a saint. Contrary to popular belief, people of faith seldom do. (For that matter, saints seldom do.) They make mistakes; they fall; they fail. Their pasts are sometimes ugly and dark, but their futures are full of beauty and light. Quite often, the clarity of purpose and inner beauty they exude after saying yes to God stand in striking contrast to who they were before they encountered God.

Cassie is a case in point. Before saying yes, she violently rebelled against her parents, experimenting with drugs and witchcraft in junior high. Inevitably, those experiments led her down the path of self-destruction and nearly to suicide. But God pulled her off that road and saved her at the very moment she said yes to Him.

While the media and politicians and educators and therapists sort through the human wreckage of Littleton, trying in vain to explain why this happened and how to prevent another Columbine massacre, I suspect Cassie knows the answer.

Simply put, maybe God is the answer.

Cassie’s killers were cold and evil men. One witness-victim-student recounts that it seemed as if Evil itself was working through them as they moved from room to room maiming and killing their classmates. The murderers did not know God. But Cassie did, and they hated her for it. They killed her for it.

While we’ll never understand all that triggered the rage and hatred of Eric Harris and Dylan Klebold, one of the contributingfactors was God’s expulsion from the classroom. It’s a chilling irony that perhaps the only time the gunmen felt free enough to mention His name in school was during their killing spree. Consider how often God’s name is noticeably absent from school, where our children spend most of their waking hours:

School systems quash official references to God--posting the Ten Commandments, praying at commencements, and staging "Christmas" pageants are things of a quaint and distant past--and frown on private ones like student-led Bible studies. God has been stricken from the textbooks, erased from the blackboard, muzzled at the lectern, and effectively chased out of education officialdom. Perhaps we can prevent another Columbine by inviting Him back.

Maybe if Columbine High had exposed Eric Harris and Dylan Klebold to stories of God’s just punishments, they would have thought twice about murdering 12 classmates and one teacher. Maybe if the gunmen had heard about His abounding mercy, they would have seen a way out of the darkness and ugliness that smothered their lives. Maybe if people like Cassie had been free to talk about God inside school, they could have helped Eric Harris and Dylan Klebold.

Most of us will never be asked to die for our faith. We are asked to do something less courageous but perhaps more arduous--to live for our faith.

Cassie was special: By saying yes, she did both.