There is no specific term that people commonly use to refer to a believer in the Greek Pantheon. The words "polytheist" and "pagan" are used, but these words are imprecise and refer to any multi-divinity pantheon.
Believing is right
Most people have stopped believing and worshipping Zeus and the other Greek gods, but it is possible that some still believe and possibly worship.
They were but believed in, believing something does not make it fact.
The word with the prefix "dis" that means in the state of not believing is "disbelief."
ballsack
Zeus only has one syllable.
People who are killed for believing in Jesus are called martyrs
atheistic
atheism
Superstitious
jesus
Jupiter.