The best spiritual defense is a good spiritual offense?
Don't you know your psalms:
Even though I walk through the valley of shadow of death, I fear no evil because I was prepared and brought kick-ass weapons and will totally whoop their butts if they come at me, bro.
Imagine a world where children are not taught the stories. How do they become believers? They can't spontaneously believe in something they know nothing about.
The same way that the first believers came about and the first religions emerged. Weird shit happens and people talk to each other about it.
It turns out that people do find personal religions on their own without having beliefs dictated to them.
The leaders make the stuff up, the followers worship it.
And that is just one of the ways in which people become religious - there are others too that you're failing to consider, or worse, just outright denying.