"I don’t hold with paddlin’ with the occult,” said Granny firmly. “Once you start paddlin’ with the occult you start believing in spirits, and when you start believing in spirits you start believing in gods. And then you’re in trouble.”

“But all them things exist,” said Nanny Ogg.

“That’s no call to go around believing in them. It only encourages ‘em."

Terry Pratchett knew how it works lol

This is new info to me, so not sure who else, but Paganism isn't a single system. It's anything the Christians were trying to erase in Europe. The wildly varying descriptions occur because it was just the negative terms applied to any other group. Going to church is a ritual. Consuming eucharist is a ritual. Priests are channels to their god. Hyms are chants. Prayers are incantations. All just negative terms applied to the out groups.