scoffer β to speak derisively; mock; jeer (often followed by at): If you can't do any better, don't scoff. Their efforts toward a peaceful settlement are not to be scoffed at.
sneer β to smile, laugh, or contort the face in a manner that shows scorn or contempt: They sneered at his pretensions.
dissenter β a person who dissents, as from an established church, political party, or majority opinion.
apostate β An apostate is someone who has abandoned their religious faith, political loyalties, or principles.
freethinker 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.
heathen β (in historical contexts) an individual of a people that do not acknowledge the God of the Bible; a person who is neither a Jew, Christian, nor Muslim; a pagan.
heretic β a professed believer who maintains religious opinions contrary to those accepted by his or her church or rejects doctrines prescribed by that church.
infidel β Religion. a person who does not accept a particular faith, especially Christianity. (in Christian use) an unbeliever, especially a Muslim. (in Muslim use) a person who does not accept the Islamic faith; kafir (def 2).
materialist β a person who is markedly more concerned with material things than with spiritual, intellectual, or cultural values.
misbelieve β to believe wrongly; hold an erroneous belief.
nihilist β total rejection of established laws and institutions.
pagan β (no longer in technical use) one of a people or community observing a polytheistic religion, as the ancient Romans and Greeks.
rationalist β the principle or habit of accepting reason as the supreme authority in matters of opinion, belief, or conduct.
profaner β characterized by irreverence or contempt for God or sacred principles or things; irreligious.