disbeliever

/ˌdɪsbəˈlivər/
noun
  1. A person who does not believe something, especially a religious or widely accepted idea.
    • The preacher spoke to a crowd of disbelievers.
    • He was a disbeliever in the theory of climate change until he saw the evidence.
    • As a disbeliever in ghosts, she laughed at the haunted house stories.
Antonyms
What does "disbeliever" mean? | whatsthatwordmean | whatsthatwordmean