That may well be, but when you are
sixteen years old, and beginning to
question everything your parents and teachers have ever told you,
revelations such as these are a big damn thing in your eyes. Right now you won't care if some
dead philosopher has already come to these
conclusions, all that matters is that
you're thinking for yourself.
When you grow up a bit more, it is very likely that you'll want to (or at least attempt to) read some of the writings from these philosophers, but statements such as these are really irrelevant.
I remember the first time I met someone who was *gasp shock horror* - an
Unbeliever such as myself. I know the feeling of 'wow, someone's already thought of this before', but it doesnt mean that your views or 'radical ideas' are any less valid.
Who cares if these
ideas of religion as a mechanism of
social control have already occured to others?
At least you're thinking them.