Why are there so many atheists in philosophy? Is this evidence that religion does not stand up to philosophical scrutiny?
Charles Taliaferro has a good point, but I feel the need to add that many intelligent religious thinkers who might be 'philosophically oriented' end up going to seminary or studying formal religion instead of going into philosophy. So, there are many attractive options open to an 'abstract thinking' religious person who wants to pursue in-depth metaphysical studies that atheists don't have. After all, if you are satisfied with relatively conventional religious answers there's no need to go into philosophy. I wouldn't read any more into the pattern than that. Finally, I'd note that the number of theists in philosophy is increasing rather than decreasing as Charles and I recently commented upon at length in another question.