I'm an atheist raised as a catholic and I would avoid any book that has been written with the premise "Let's write a christian novel".
That being said, I've read one book where religion is important but not obnoxious. Not in your face. It genuinely adds flavor to the book and makes it richer:
"Canticle for Leibowitz" - Walter M. Miller, Jr.
A post-apocalyptic novel, one of the first and among the best ones.
Generally about religion in Fantasy or SF - it seems to be a taboo topic, which is strange to me. In 95% cases you get either whole nations with no religion, or essentially renamed and thinly disguised Christianity, or some ridiculous "evil god" worship that doesn't even try to sound plausible.