I once visited my grandparent's church when I was four or five and remember looking at them and wondering how they could still believe in God at their age. I had written off the idea of Santa and the tooth fairy as nonsense from the start, and I didn't have much time for God either as he seemed to be the same kind of fish, but they were still listening to all that claptrap about him and seemed to take it absolutely seriously. It puzzled me for a long time, but I eventually realised that it was all about the promise of life after death and their desire to be reunited with people they'd lost. It is 100% wishful thinking.

Wish I knew better earlier, but pre-teens is enough.