In his extensive world travels, Guy P. Harrison discovered that religious people everywhere, regardless of which particular religious tradition they belong to, tend to offer the same reasons when asked why they believe in god(s). He also discovered that few of these arguments have anything in common with the kinds of reasons theologians offer (a point which theological critics of popular-level atheological writers like Hitchens and Dawkins keep failing to understand—the Four Horsemen don't bother with Aquinas because no one outside of the academy does). Finally, he discovered that none of these reasons are much good in the end. The result, 50 Reasons People Give for Believing in God.
50 Reasons is a good addition to the corpus of critiques of popular religion. It is very easy to read, most of its arguments are sound, and, most importantly for me, it makes a few novel points, at least in its emphasis. One of them, repeatedly stressed throughout the book, is something which I already knew, but which I never appreciated before, despite having the figures right there, staring me in the face: no matter what religion you belong to, even if you define your religion fairly broadly (like "Christianity" or "Islam"), there are at least four billion people in the world who think you're wrong. Every religion is in the decided minority. We so often tend to take whatever religion dominates our surroundings, together with its conception of the divine, as the default. A little travel, a little broader perspective, should at least shake our conception of what the obvious contenders are.
(I actually have wondered about something related to this, but applied to the academy. I notice that the way philosophers of religion, particular the evangelical ones, argue, it is as though they believe that Christianity and naturalism are the only two options. They will do things like try to show that, as evidence for the existence of god, the cosmological fine-tuning argument "outweighs" the argument from evil. How ridiculous! Why not accept them both—that the former argument shows that there is a god, and the latter shows that the god in question is evil or uncaring? And, yet, that option is not even on the table for them. Why shouldn't it be?)
I was a little surprised by the size of the book: for some reason, I had expected brief, 1-2 page entries, like the kind of thing I am doing in my Atheological Thoughts web series, but the book is actually a hefty 354 pages. I also thought that Harrison did not come across nearly as sympathetically as he seems to think he does, even though he is folksy and good-humored throughout. In any case, though, it is a good book. I recommend it if you care about the reasons why most people believe; if you prefer to fence with Oxford dons and Aquinas scholars, look elsewhere, and may the devil take you.