Indoctrination is hard to break. It can take years to unlearn the cyclical reasoning Christianity teaches "I'm right because I(god) said so." Some people probably don't have the intellectual capacity to overcome it. Basing beliefs on reasoning/logic and empirical evidence is so freeing, but I think many fear it not only because reality sometimes means no explanation (meaning of life, for example) but also because the Bible teaches against using logic and evidence if it conflicts with the Bible and threatens eternal torture for defectors.