Belief is Irrational
If you believe in invisible, intangible beings with magical powers, you can NOT claim to be 100% Rational.
This doesn't mean you are unintelligent, stupid or insane. It means what it says, you can not lay claim to being completely rational.
Christianity: A disgusting middle eastern blood cult, based in human sacrifice, with sacraments of cannibalism and vampirism, whose highest icon is of a near naked man hanging in torment from a device of torture.