Almost all religious people have doubt enough to consider how it would feel not to believe.

This is not my idea of what "doubt" is. I've spent all my life as a big, hairy, gruff man, but I've often considered what it might be like to be a woman. This does not reflect any doubt at all on my part that I'm a man. Incidentally, I should like to have the survey results that demonstrate the levels of doubt you appear to be claiming. Almost all, eh? I have my doubts.