Angels and demons do exist and to engage with them one just needs to do so with the standard occult rituals to invoke and/or bind them. Aleister Crowley explained it. Alan Moore’s new Moon and Serpent Bumper Book of Magic lays it out in graphic novel format.

The Lesser Banishing Ritual of the Pentagram works.

So many seeming “mysteries” of religion do have answers and they’ve been readily available for generations. People just don’t want to feel silly waving around a magic wand and thinking it will actually work. And the answers to be found here are more unsettling than most people can handle so there are legitimate reasons why this stuff has been made “occult.”