The folks in the marketing department at my publisher didn't like the title of my latest book (The Burning Land), so my editor asked me to come up with some alternatives. They liked these even less, and I wound up with my original title by default...but my editor told me that our number 2 choice, The Dreaming God, was rejected specifically because of the religious reference. Obviously this will vary from publisher to publisher and book to book (Eos also went to quite a bit of trouble in the flap copy to avoid revealing the fact that the hero is a priest), but a Biblical sounding reference may not go over well.
Of course, if the book is bought you often won't wind up with the title you choose anyway, so the point may be moot. It might not be a bad idea, though, to stay away from anything with Christian connotations (unless of course you're writing for the Christian market).
- Victoria