1) Agnostic 2) Doubter 3) Nonbeliever 4) Nonreligious person 5) Sceptic 6) Unbeliever 1) Atheist 2) Critic 3) Cynic 4) Irreligionist 5) Nonbeliever 6) Unbeliever 
• (n.) One who disbelieves, or refuses belief; an unbeliever. Specifically, one who does not believe the Christian religion.
Dis`be·liev'er noun One who disbelieves, or refuses belief; an unbeliever. Specifically, one who does not believe the Christian religion. I. Watts. 
[n] - someone who refuses to believe (as in a divinity)
nonbeliever noun someone who refuses to believe (as in a divinity)