This is a spiritual event. Those are the words that rolled through Darrell Scott’s mind as he fought Denver traffic on April 20, 1999, trying to reach Columbine High School. He had heard news stories about shootings there, where two of his children — Craig and Rachel — and a niece and nephew were students.

He didn’t know anything at that point; few people did. He didn’t know that two students were intent on killing as many people as they could. He didn’t know that his son Craig was crouched under a library table, flanked by two friends who were already shot to death. (Craig feigned death himself and later led some students to safety from the library.)

Darrell didn’t know that his 17-year-old daughter, Rachel, had been gunned down outside the building. (She had just been wounded at first, but was shot to death, point blank, when Eric Harris came back and asked if she, a known Christian, still believed in God. When she said, "You know I do," Harris shot her.)

All Darrell knew as he navigated the roads for 35 minutes, he says, is that the same words kept cycling through his mind: This is a spiritual event.

Now, a year later, we know almost as much as we ever will about that terrible day. As Darrell says in the message he now preaches around the United States, this event will have the same impact as the assassinations of John F. Kennedy and Martin Luther King did for the previous generation. Where were you when you heard the news? (I was at my office, only 55 miles from the school, scrolling through the AP Web site during my lunch hour, when the first bulletins started to appear.)

We know who the two killers and 13 victims were. We know most of what they did, where they did it, when they did it and how they did it. What we may never know is why.

To be sure, there’s plenty of speculation. All it takes is a Web search on "Columbine High School." Browse through the 10,000 or more hits to find all the pet theories articulated during the past 12 months, most with some political agenda lurking in the background.

Too little gun control — or too much. (One of the more idiotic sites states that the "real reason" so many people died was that the victims didn’t know enough about guns to realize that after firing two blasts from a shotgun, a gunman would have to stop and reload, giving them ample opportunity to rush him! If only they’d been taught how to handle guns, then they would have been able to save themselves, the writer complained.)

Schools with too many students or too few counselors.

Parental involvement, or lack of it.

Violent video games, movies and rock music.

Even Darrell Scott has his theory: that the absence of prayer in schools since 1962 has opened a spiritual vacuum in schools, leaving them open to this kind of horror.

It’s hard to argue with a man who has suffered such loss, but the truth is that no one except God really knows why Eric Harris and Dylan Klebold did what they did; those two young murderers may not have even known what fueled their rage. It is a mystery.

This isn’t to say we shouldn’t look for answers or try to delineate reasons for what occurred. But determining the underlying causes of something like Columbine is not like doing math. There is not a single satisfactory answer.

Were there problems in the Harris and Klebold homes that allowed the boys (just boys!) to plot and prepare for their assault?

Was there some kind of breakdown in communication with the local law-enforcement agencies that allowed them to miss signals about the boys’ intentions?

Were Harris and Klebold affected by violent media, particularly video games such as Doom?

Were firearms and explosive materials too accessible for them?

Was security lax at Columbine?

Were there social schisms in the school—cliques and pseudo-gangs that were more exclusive than inclusive—that provoked jealously and hatred?

Is there a spiritual vacuum, or at least spiritual confusion, in society and in schools?

Maybe. Probably. Yes. The same answers apply for each question. But which single factor led to the killing? It’s not that simple.

Trying to decipher Columbine is not like doing math, trying to find the single correct answer, like two plus two. It’s more like chemistry, trying to figure out the particular formula of a compound. These ingredients are present, in various ways, at virtually every high school in America. But so far there have been only a few shootings and only one Columbine. What was the particular mixture there that blew up into death and destruction? That’s the mystery, one that will never be figured out on this side of eternity, especially if we insist on looking for simple answers.

Comes, the powers of hell to vanquish, As the darkness clears away ... That’s not the only mystery, however. What is just as great a mystery is how people have responded in the aftermath. Some reactions are understandable and even predictable: families are filing lawsuits, for example. Some teachers and students are undergoing counseling, struggling just to make it through each day when they have to walk the same halls where they saw so much blood and felt so much pain only a year ago.

On the other hand, most Columbine teachers and students are functioning well. The school itself has reopened. Teachers make assignments and cover their lessons. Students go to class, write their papers and finish their homework. They laugh and play and look forward to graduation. They are scarred, but they are alive in every sense of the word. That, too, is a mystery.

The families of the victims have gathered strength from each other, enough to spearhead a $3 million fund-raising project to tear down the current school library, which will never reopen, and build a new one. That families in such pain can find the endurance and purpose to work for such a project is a mystery.

What about the documented evidence that a few of the victims, particularly the Christians among them, were somehow prepared for this? Rachel Scott, for one, seemed to have a premonition that her life would be cut short, and instead of thinking she was going crazy took it as a sign that God had something special in mind for her. And, according to her father and mother, more people watched Rachel’s funeral, televised on CNN, than Princess Diana’s. With the service’s strong Christian content, thousands of teens dedicated themselves to Jesus Christ, inspired by Rachel’s example.

And what about parents like Rachel’s, Darrell Scott and Beth Nimmo? They have written a book (Rachel’s Tears: The Spiritual Journey of Columbine Martyr Rachel Scott, Nelson), and Darrell spends his time traveling around the country, speaking at churches and schools. He doesn’t spend time or energy placing blame or bemoaning the "system." He tells his daughter’s story — about her faith, about her willingness to live — and die — for Jesus. And he challenges the audience, particularly high school and college students, to follow the same kind of path. It is a joyful, hopeful, meaning-filled message.

He started preaching this less than three months after the shootings. How? Where does the strength come from? He says it is from God. He and Rachel’s mother — and, I suspect, all the parents and relations and close friends — still sob in grief. But they do not only grieve, and they are not despondent or hopeless. Considering what they’ve faced, how can that be?

That is a mystery, one that should render we who are on the outside speechless.

Thanks to the intricacies of the lunar calendar, the first anniversary of Columbine falls on Maundy Thursday, which commemorates the last day of Jesus’ earthly life before his crucifixion, and on the Jewish Passover, which commemorates the Jews’ liberation from slavery. Those biblical events are mysterious too. How could the death of God’s son work for good? Why would God work in the way he did? Why did Jesus have to die at all? Why were the people of Israel subjected to slavery for centuries, and why did they have to sacrifice a lamb as they waited to be liberated?

Theologians have struggled with those kinds of questions for centuries, and there are myriad answers, but not one complete in itself. As with Columbine, we can only partially understand now; one day we’ll understand fully. Maybe.

Until then, it’s good to occasionally stop trying to answer the "why" questions, and just stand in silence. Every so often we need to be struck dumb by terror and awe, terrified at the power of evil and awestruck at the greater power of God. This is a spiritual event; we stand on holy ground.

Remember the words of an ancient hymn:

Let all mortal flesh keep silence, And with fear and trembling stand; Ponder nothing earthly-minded, For with blessing in his hand Christ our God to earth descending Comes our homage to demand.

King of kings, yet born of Mary, As of old on earth he stood, Lord of lords in human vesture, In the body and the blood, He will give to all the faithful His own self for heavenly food.

Rank on rank the host of heaven Spreads its vanguard on the way; As the Light of light, descending From the realms of endless day, Comes, the powers of hell to vanquish, As the darkness clears away.

At his feet the six-winged seraph, Cherubim with sleepless eye, Veil their faces to the presence, As with ceaseless voice they cry: "Alleluia! Alleluia! Alleluia, Lord Most High!"