If theists were rational, then religion would be fine. As it is, and knowing how the vast majority of people are, religion is like handing over the car keys to your six year old. Or giving him a box of kitchen matches on his birthday. You tell people that they MUST follow this or that diety's guidelines (which are, of course, made up by some dudes) or they'll be in some sort of eternal trouble. And then when some yahoo comes along and takes a different approach to the rules, like female genital mutilation, we expect that people won't follow that dude's ideas? How foolish. This is just one example of how the mindset of superstition and doing without thinking (i.e. faith) is just about the worst idea humans ever had.