Well, I finished a book a week ago, which, though not a book about religion, was definitely informative for my current thought process. It's called The Blank Slate: The Modern Denial of Human Nature
by Steven Pinker. Pinker does talk about religion, but only in terms of what religion says about personality, and how that lines up with or contradicts science. In terms of religion, and specifically in relation to the question of a non-material part of the personality (a soul, or what not), all the evidence is that there isn't anything non-material to our humanity, consciousness, or personality. Now, this isn't absolute, it's just our best understanding of the mind, but for me, the burden of proof is definitely on the side of the non-materialists in this arena.