Sceptic: a person inclined to question or doubt accepted opinions. Ascetic: characterized by severe self-discipline and abstention from all forms of indulgence, typically for religious reasons. Devotee: a person who is very interested in and enthusiastic about someone or something. Antiquarian: relating to or dealing in antiques or rare books.
Prostate: a gland surrounding the neck of the bladder in male mammals and releasing a fluid component of semen. Profane: (of a person or their behaviour) not respectful of religious practice; irreverent. Agnostic: a person who believes that nothing is known or can be known of the existence or nature of God. Apostate: a person who renounces or abandons a religious or political belief or principle.
The one word-substitution is Alliteration.
Pun: A joke exploiting the different possible meanings of a word or the fact that there are words which sound alike but have different meanings. Transferred epithet: A transferred epithet often involves shifting a modifier from the animate to the inanimate, as in the phrases. Oxymoron: A figure of speech in which apparently contradictory terms appear in conjunction. Alliteration: The occurrence of the same letter or sound at the beginning of adjacent or closely connected words.
Person who does not believe in the existence of God:
Theist: Belief in the existence of a god or gods, specifically of a creator who intervenes in the universe. Heretic: A person believing in or practicing religious heresy. Fanatic: A person filled with excessive and single-minded zeal. Atheist: A person who disbelieves or lacks belief in the existence of God or gods.