noun

belief or opinion contrary to orthodox religious (especially Christian) doctrine.

Huss was burned for heresy

dissension,dissent,dissidence,blasphemy,nonconformity,unorthodoxy,heterodoxy,apostasy,freethinking,schism,faction,scepticism,agnosticism,atheism,non-theism,non-belief,unbelief,idolatry,paganism,separatism,sectarianism,revisionism,tergiversation,recreancy,recusancy