In Sam Harris's book, End of Faith, he makes a strong point about how moderate believers allow the extremists to exist by validating the holy books which they literally interpret.   My question of those moderate members of religions is how would you attempt to argue against a fundamentalist?  If you both accept that the bible/koran is the word of god, or inspired by the word of god, how can you argue that the fundies are wrong?  Espicially when they are more faithful to the text in question, not attempting to explain away the more vicious excepts by saying they are exagerations or metaphors?