heretical

adj

1. Of or pertaining to heresy or heretics.

   “At least as Auxentius reports him in the covering letter which precedes Ulfila’s confession, he is as vehement in his opposition to what he sees as heretical alternatives to his own form of belief as most other participants in the controversies of the time. Heretics are not Christians but antichrists. Homoousians, Homoiousians, and Macedonians are all included in this blanket condemnation.”

2. Contrary to mainstream or accepted opinion.