Because people don't believe it unless it happens to them.

[...] so important to believe in a concept of goodness, even if we make it up ourselves. We don't really make it up. it's there, isn't it?" "Oh, yes, it's there," she said. "It's there because we put it there.

I cannot mislead people into believing that I support organized religion. In Jesus' name, I cannot be complicit with many of the things organized religion does.

People who cease to believe in God or goodness altogether still believe in the devil. I don't know why. No, I do indeed know why. Evil is always possible. And goodness is eternally difficult.