I remember my High School French teacher. She was a very intelligent woman with a strong character. One day, I discovered she was a Christian, which, to me, back then, was mutually exclusive with "intelligent". And I remembered a story she told us once, about her daughter. Her daughter had leukemia and slowly died because of it. She was a young girl, maybe ten or twelve. Our teacher told us that for an entire year after her death, she cried every night. I don't know whether she was a believer before this tragic event, but chances are she wasn't, though that's only a guess. The point is that if your own child died this way, you'd be seriously upset at life, and you would demand a reason. You would need some sort of an explanation, because you can't live without one anymore. That's when it becomes important that life actually make some sense.