In one of my countries, there exists a group of bug-like people who worship a god trapped inside of a tree. They hold ceremonies, obey her every command, and they never, ever leave the small city they created. There is also a high priest, who:
- creates and shares visions he shared with the goddess
- tries to introduce outsiders and force them to stay
- holds ceremonies in her name
I was wondering how to flesh out this idea more realistically, since I am pretty unknowledgeable on the religious front.