Step 1: Understanding the term.
- A theist is one who believes in the existence of God.
- A devotee is a person who is deeply devoted to worship or service of God.
- A worshipper is one who shows reverence and adoration for God or a deity.
- An atheist is one who denies or does not believe in the existence of God. Step 2: Conclusion.
Since the question asks for a person who does not believe in God, the correct term is atheist. Final Answer:
\[
\boxed{\text{(atheist}}
\]