The future came and went in the mildly discouraging way that futures do. - Neil Gaiman

"The little folk dare anything", said his friend. "And they talk a lot of nonsense. But they talks an awful lot of sense, as well. You listen to 'em at your peril, and you ignore 'em at your peril, too."

“The old religion.”
“Druids?” asked Shadow. He was uncertain what other old religions there were, in England.
“Could be. Definitely could be. But I think it predates the druids. Doesn’t have much of a name. It’s just what people in these parts practice, beneath whatever else they believe. Druids, Norse, Catholics, Protestants, doesn’t matter. That’s what people pay lip service to. The old religion is what gets the crops up and keeps your cock hard and makes sure that nobody builds a bloody great motorway through an area of outstanding natural beauty. The Gateway stands, and the hill stands, and the place stands. It’s well, well over two thousand years old. You don’t go mucking about with anything that powerful.

Write your story as it needs to be written. Write it honestly and tell it as best you can. I'm not sure that there are any other rules. Not ones that matter.