Some researchers have speculated that religion itself may have played an important role in getting large groups of prehistoric humans to socially cohere. If this is true, we can say that religion has served an important purpose. This does not suggest, however, that it serves an important purpose . There is, after all, nothing more natural than rape. But no one would argue that rape is good, or compatible with a civil society, because it may have had evolutionary advantages for our ancestors. That religion may have served some necessary function for us in the past does not preclude the possibility that it is now the greatest impediment to our building a global civilization.
Sam Harris