Fanaticism.
Synonyms:
bigotry, credulity, intolerance, superstition.
Fanaticism is extravagant or even frenzied zeal; bigotry is obstinate and unreasoning attachment to a cause or creed; fanaticism and bigotry usually include intolerance, which is unwillingness to tolerate beliefs or opinions contrary to one's own; superstition is ignorant and irrational religious belief. Credulity is not distinctively religious, but is a general readiness to believe without sufficient evidence, with a proneness to accept the marvellous. Bigotry is narrow, fanaticism is fierce, superstition is ignorant, credulity is weak, intolerance is severe. Bigotry has not the capacity to reason fairly, fanaticism has not the patience, superstition has not the knowledge and mental discipline, intolerance has not the disposition. Bigotry, fanaticism, and superstition are perversions of the religious sentiment; credulity and intolerance often accompany skepticism or atheism.
Antonyms:
cynicism, free-thinking, indifference, latitudinarianism.