“In every generation, each person must feel as if he personally had come out of Egypt, as the Torah says: “You should tell your child on that day, ‘When I left Egypt, Hashem (god) did miracles for me …..’ ” from The Haggadah (prayer book for Pesach)

… You should tell your child to question what he is told (especially things you yourself find dubious).
… You should tell your child that he is free to think for himself, and that you will love him regardless of his beliefs, or lack there of.
… You should also tell your child… that the history of religion is in no way accurate, nor is it necessarily ‘moral’.

perhaps you should NOT tell your child… but rather, listen.