[Steelwheat]

Satanism isn't really a single organized religion, you could say that it is an offshot from Christianity as Satan is a figure from the Christian bible/Abrahamic religions. There's LaVeyan Satanism, which is more of a sort of libertarian philosophy that doesn't actually believe in a literal Satan but uses Satan as a symbol of freedom and sort of has an occultic aesthetic, which is most common. It isn't actually a bad philosophy, really. There have been various theistic Satanist groups as well.