Steve, I think some people are simply literal-minded. No amount of explanation is going to take them to any depth. And when literal-minded people get involved in religion, the results can be dangerous.
But people who are able to think beyond the literal meaning of things, usually don't need an explanation. And in many years of teaching kids religion, I've found that kids are less likely than adults, to get stuck in literalism. If you're a halfway decent teacher, they catch onto what you're trying to convey.

-Joe-