Tolkien was heavily inspired by Norse mythology. If you haven't already read the Lord of the Rings trilogy, I highly recommend it. There's no sex or swearing and everyone's favourite hairy-footed protagonist is 50 years old at the start of the adventure. Also, Tolkien was Catholic but he doesn't mention religion at all in the trilogy. (If he does I missed it.)
Although it's not in novel form, you could also get your fix of Norse myths by going straight to the original source: the Eddas. You can read an old translation for free here:
http://www.gutenberg.org/files/14726/14726-h/14726-h.htm
If you want to read something light and humourous like Hitchhiker's Guide, try Terry Pratchett and Neil Gaiman's Good Omens or any of the Discworld books by Pratchett. (Although maybe everything in that giant series counts as YA. I am not sure.)
