Aren’t the Yazidis devil worshippers? The idea being God is good, won’t hurt them, but the devil on the other hand would.
They’re often colloquially referred to as “devil worshippers” but they object to the characterization. They believe more in a dualist view, like the gnostics, and see a force of good and evil in opposition that are both necessary. Surely heretical from a Christian perspective, but not quite “devil worshippers” I would say.