A child of God and a devil worshipper are in opposition.

I’m developing my first feature screenplay right now and it’s about a father and a son and how their fate is interconnected through a prophecy.

The son is a child of god (devout catholic) in an attempt to atone for what his father has done, while the father is worshipping the devil (cult leader) and using supernatural elements to communicate and try to coerce the son into fulfilling the prophecy.

I can add a little more detail if anyone is interested but I’m wondering what are some ideas or references on how demonic and cult rituals work either in real life or in film. It’s something I’m interested in exploring. I’ve seen hereditary and that’s my one time exposure to the concept.

Thank you for your time :)