pagan
A person who follows old religions with many gods.
Pagan originally meant someone who lived in the countryside or a rural village. In ancient Rome, as Christianity spread through cities, the old polytheistic religions (worshipping multiple gods like Jupiter, Venus, and Mars) lingered longer in rural areas. Christians began using “pagan” to describe people who still followed these traditional religions rather than Christianity.
Today, historians and scholars use pagan to refer to the ancient polytheistic religions of Europe and the Mediterranean world before Christianity became dominant. The ancient Greeks who worshipped Zeus and Athena were pagans. The Vikings who honored Thor and Odin were pagans. The Romans who built temples to their many gods were pagans.
Some people today call themselves neopagans or modern pagans, meaning they practice contemporary versions of these ancient nature-based religions. When you read about pagan festivals in history books, you're learning about celebrations and rituals from these old belief systems.