I remember having this problem myself from as far back as I can remember (first clearly dated memory involves a crib mobile, so, yeah, pretty far back)
When I was 12 I gave myself a talking to, and decided to stop asking the question, because I was getting incredibly frustrated and becomming totally and utterly non-functional as a human being. It took me a few months to "quit," but I did, and when I came back to it at 15, I was more equipped to handle it. Sort of. Of course I got myself into a whole lot of trouble over it, and eventually converted to a different religion.
I think a lot of kids go through this (most, probably to a lesser extent, though

), and based on my experiences, by the time I was 3, talking to people about it was the worst possible thing, because absolutely NO-ONE could follow my explanations. It made me feel intensely isolated to discuss it... to the point of being suicidal from sheer lonliness. I don't think my thoughts were so unusual, but I think I didn't have a vocabularly to discuss it that was recognisable to others. So instead of "helping" a normal, thoughful teen, I think it's probably safer to just give him the tools to work though it on his own and not meddle too much, especially if he doesn't want to talk.
If I saw signs of the same thing happening in my kid as a teenager, I'd invest in art classes, and a large gift certificate to a religion and philosophy book shop *and not go with him to the bookstore*
2 cents from someone who was "intense" about this

Michaela.