thinking faith was childish when I only meant that I’d been a child the last time I took it seriously

Q. You say you came back to religion “freely, as an adult, after 20-odd
years of atheism.” Can you describe your initial switch to atheism?
How old were you? Were there particular texts or experiences that
influenced your move away from religion?

A. Oh, it was just the usual teenage discovery that the world is a lot
larger than childhood’s ordering of it. I was in a church-going
family, and at thirteen or fourteen I started caring a lot more about
sex, music and politics than I did about God — and the box of
symbolism and stories I’d left behind seemed to shrink as I moved away
from it, until it was impossible to imagine ever fitting inside again.
In fact I made the classic mistake of thinking faith was childish when
I only meant that I’d been a child the last time I took it seriously.
I was never argued out of faith, it was much more passive than that —
and I wasn’t argued back in, either.

- Francis Spufford in New York Times interview
 http://artsbeat.blogs.nytimes.com/2013/10/24/despite-everything-francis-spufford-talks-about-unapologetic/?_r=0