In the 13 years he's been in ministry, the Rev. Larry Breeden has offered his shoulder to grieving parents who've lost their children in car accidents.

He's prayed outside emergency rooms and offered words of comfort at funerals.

He's spent long days in food pantries packing groceries for Hurricane Katrina victims.

But he'd never had to respond to anything like the massacre at Northern Illinois University. Until Feb. 14.

"I think it was a struggle because of the picture I have in my mind of being in a classroom like that … It's harder because you can identify with that," said Breeden, campus pastor at Christ Community Church in DeKalb. "You wonder what you would do in a situation like that, and your heart goes out to the people who were there."

The reason for the killings may always be a mystery. Authorities continue to investigate the motive of the heavily armed shooter who entered a crowded lecture hall and opened fire before killing himself. The rampage left five students dead and 16 others injured.

Beyond the specific reasons of a disturbed individual are the questions that ministers like Breeden get about how such evil can occur.

Answers are fleeting.

But as NIU prepares to host a memorial service tonight on the eve of classes resuming, religious leaders try to address that question nonetheless.

"We can't really understand it," said Mark Laboe, associate vice president for university ministry at DePaul University. "Life and faith in many ways is about the questions and about striving and seeking to understand."

But, he added, from the Roman Catholic theological perspective, "to understand the question why do things like this happen, we might first sort of understand that we as human beings are sinful people. We're broken. We're not whole. We're capable of evil, of wrongdoing, of misunderstanding, of losing perspective. This is all part of being human."

The major faith traditions teach that human beings operate under free will, which means they can choose either good or evil.

But that doesn't necessarily take into account the effects of mental illness on free will, said Rabbi Yehiel Poupko, Jewish scholar in residence at the Jewish United Fund/Jewish Federation of Metropolitan Chicago.

"The source of evil is either human free will or human illness. And, of course, if someone is ill and chooses evil, the consequences are horrible, and you can't call it evil," Poupko said. "The question is, did (the shooter) know the difference between right and wrong?"

The NIU shootings have an impact far beyond northern Illinois, said Imam Abdul Malik Mujahid Malik of the Council of Islamic Organizations of Greater Chicago.

He pointed to a verse in the Quran: "If anyone slew a person … it would be as if he slew the whole people; and if anyone saved a life, it would be as if he saved the life of the whole people."

Malik called on religious leaders to speak out against what he described as a culture of violence in America.

"There's a need for an interfaith movement against the easy access to guns," Malik said.

On a broader level, our response should be one of compassion, no matter how difficult, Poupko and other spiritual leaders said.

"When someone has been affected by evil, you respond by acts of loving kindness," Poupko said.

Timothy Larsen, McManis professor of Christian thought at Wheaton College, echoed those thoughts.

"I think that the Christian response is not try to answer the question, 'Why did this happen?' but (ask) 'How would God have me respond?' Christian spirituality teaches us to think about how am I to live in light of these situations. What kind of response of compassion, what kind of hope for the future can I have in this context?" Larsen said.

According to the Bible and Christian tradition, Jesus, while he was being crucified, looked up to heaven and asked, "My God, my God, why have you forsaken me?"

"That's God willing to experience what it's like from our end," Larsen said. "And what it's like from our end is having a question rather than an answer."