unbeliever means one who does not believe, particularly in a deity (used by believers to describe people who do not believe in the same deity or deities as themselves). Lexicurio rates it Rare gem — a strength score of 78 out of 100.
Why “unbeliever” is a great word
UNBELIEVER — [Noun] One who does not believe, especially in a specific religious faith or deity. From the prefix un- ("not") + believer, with first attestation in the 1520s. Unlike "infidel," which historically brands an outsider as an enemy, or "agnostic," which articulates a philosophical stance of uncertainty, "unbeliever" is the simple, declarative fact of absence. It is the untouched wafer on the tongue, the respectful silence after an "Amen," the space in the pew where a family member once sat—a void defined not by hostility, but by the quiet persistence of a different shape of mind.
noun
- One who does not believe, particularly in a deity (used by believers to describe people who do not believe in the same deity or deities as themselves).“`Well, I suppose that we must try it,' I said; and the others assented in their various ways - Leo, as though it were the best joke in the world; Job, in respectful disgust; and Mahomed, with an invocation to the Prophet, and a comprehensive curse upon all unbelievers and their ways of thought and travel.”