theist; deist
Refers to a person who believes in a god or gods. In Japanese, the distinction between theism and deism is often not strictly made without additional context.
He is a theist and goes to church every week.
The debate between theists and atheists continues.
Means 'atheist', the opposite of 有神論者.
More specifically means 'deist', emphasizing a non-intervening creator, while 有神論者 is broader.
Compound of 有神論 (theism) + 者 (person). 有神論 is from 有 (existence) + 神 (god) + 論 (theory).