Did you choose your religion, or did your parents choose it for you?
You have a point. This is how they maintain their ranks, if we put it this way - include children in religion while they still don`t have their own opinion and thus can`t choose to join or not.
The most rational solution is to wait until a child is grown up so he can decide for himself. Religious upbringing steals free will from a person, though I think religious people will disagree.
No offence meant, I am just sharing my opinion on upbringing - the way I will choose with my own children.