He asked me to define religion. Not heaven and hell, but the concept of religion as a whole. I admit it, I'm stumped. Any suggestions would be greatly appreciated!
Give him
The God Delusion to read and then discuss with you? ;-> But seriously... If asked "what's religion?" I'd say "for example, Christianity, Islam, .... are religions". If asked literally to define religion, I'd say "well, it's difficult to define, but it's when people believe in one or more gods". You probably then get "what's a god?" and "what do you believe?" and away you go... I think provided you don't feel as though you have to encapsulate the whole concept, so that there's no more to be said, in a few words, you'll be OK! With DS5, I do not (consciously) attempt to simplify such things: I just explain to the best of my ability, using the same words I'd use to an adult. Seems to work in the sense that he learns some things and it satisfies him, although it can happen that he returns to a subject the next day too.
(In conversation with DS5 this afternoon, it emerged that he thought that if someone was Christian it followed that they didn't think natural selection worked. Don't know whether he's encountered someone who really didn't or merely inferred it from what David Attenborough said on some DVD about the early effect of Darwin's ideas! But cue earnest conversation, as I think his assuming that every Christian he meets in his Christian-foundation school is a creationist could get him into serious trouble!)