pagan (noun) [pronounce pay-gan] – an unbeliever or someone who believes in gods that don’t belong to one of the three big religions (Christianity, Islam or Judaism).
pagan or paganistic (adjective) – connected to pagans
paganism (noun) – the belief in other gods or not believing at all
Note: This word is often offensive.
Here are some examples of how you’ll find pagan used:
The pagans were dancing around a big burning tree.
The Celts were pagans who had druids for priests and who believed in lots of different gods and heroes.
Christian monks in the Middle Ages were ignorant of pagan rituals among the peoples they preached to.
Archaeologists have found signs of paganistic sacrifices outside the temple.
He believes in a strong determining force that doesn’t come from God. So essentially what he believes is a form of paganism.
Druid Ceremony at Stonehenge, UK
Note: Other Words for Pagan
The three monotheistic religions that I mentioned all have their own favourite word for a person who doesn’t believe in their particular brand of god-worship:
Christians like to call nonbelievers (in Christianity) heathen.
Muslims call nonbelievers infidel.
And Jews call nonbelievers gentile.
All these three words can be pretty offensive, depending whom you are speaking to.
Finally, if you’re looking for a word for nonbelievers that is inoffensive and not connected to any religion, use atheist. (This literally means non believer in a god.)