the line is very fine, and yet very coarse at the same time.
frankly, if i were a pr person, i'd tell people to stay away from it, because it's far too easy to get it wrong. you're not supposed to talk about religion at dinner parties, right? well, maybe you shouldn't write records about it, either.
but, when it gets into people's heads, it's hard to get it out, and it takes over your life. it's easy to tell people not to write songs about god, but if that's where their heads are, there's often not much else they want to write about. and, then they end up lost to the world of art within a short amount of time, afterwards.
so, yes - you can write religiously themed music that appeals to atheists, anti-theists and skeptics. it's just very dangerous to try, if that's what your fan base mostly is, because if you screw it up, it could be fatal.