Heterodox
Definition
adj. Not in agreement with accepted beliefs; holding unorthodox opinions
Synonyms
dissident
doubtful
skeptical
Antonyms
orthodox
conformist
conventional
Sentences
Galileo's first discoveries were first seen as heterodox because it wasn't what the church believed, but now his ideas are widely accepted.
Christians see atheists as heterodox because they don't agree with their beliefs.