Religion is handed down from fathers to children as the property of a family with the burdens.
Very few people in the world would have a God if care had not been taken to give them one. Each one receives from his parents and his instructors the God which they themselves have received from theirs; only, according to his own temperament, each one arranges, modifies, and paints Him agreeably to his taste.
Ignatius Loyola allegedly said “Give me the child and I will give you the man” although he may not have – some claim that it was a calumny laid on Loyola by Voltaire. Aristotle said:
“Give me a child until he is 7 and I will show you the man.”
These creepy observations reach for a deep truth: children are easier to fool into believing in gods. Imagine if you had an adult who grew up without any “knowledge” about gods, and you tried to explain it to them.
Humans are meta-programmed creatures – we’re not born as completely “blank slates” but a tremendous amount of what we are and how we operate is learned. It seems to make sense to me that a human child (or any animal that has complex learned behaviors) is going to have a critical period in which it is more accepting of instruction. If children were born as little skeptics and kept asking parents “why?” “why?” “why?” (like I did!) the species would probably die out when nobody decided to have children any more. So: get them young, and get the bullshit over the goal-line so it becomes part of their world-view. You can polish it with all the detailed nonsense later.