atheism β Atheism is the belief that there is no God. Compare agnosticism.
unbelief β the state or quality of not believing; incredulity or skepticism, especially in matters of doctrine or religious faith.
doubt β to be uncertain about; consider questionable or unlikely; hesitate to believe.
scepticism β skeptical attitude or temper; doubt.
skepticism β skeptical attitude or temper; doubt.
incredulity β the quality or state of being incredulous; inability or unwillingness to believe.
freethinking β a person who forms opinions on the basis of reason, independent of authority or tradition, especially a person whose religious opinions differ from established belief.
disbelief β the inability or refusal to believe or to accept something as true.
renunciation β an act or instance of relinquishing, abandoning, repudiating, or sacrificing something, as a right, title, person, or ambition: the king's renunciation of the throne.
guess β to arrive at or commit oneself to an opinion about (something) without having sufficient evidence to support the opinion fully: to guess a person's weight.
guesswork β work or procedure based on or consisting of the making of guesses or conjectures.
hunch β to thrust out or up in a hump; arch: to hunch one's back.
idea β any conception existing in the mind as a result of mental understanding, awareness, or activity.