I wouldn't go as far as to say that no-one
Kinda late answer but anyways, I wasn't referring to "no-one", I think about it more like - even if somebody is fe 25 so he is not a kid, if he was indoctrinated into one religion values we can't say he has got a spiritual understanding, you need to have a far deeper understanding about all religions and ethics. But that only happens in societies that are on the fringe. I agree with the children aspect - it's everywhere like that, you've got a "young protestant" or a "little catholic" even before they can actually understand what it means to be one. On the other hand in some societies it might be very hard to explain to a kid why he ain't attending with ALL the other kids to f.e. catholic religion lessons, or ceremonies - he might get isolated by other kids because he is different.