Worshippers of Satan see themselves as spiritualists for whom Satan is an actual deity and a figure symbolising crisis of faith, individualism and free will.
Certain sects of this religion are notorious. For instance, the ‘Beasts of Satan’ committed murders in Italy between 1998-2004. The ‘Order of Nine Angels’ affirmed human sacrifice in (the 1960s).
The practice became more widespread with the establishment of the Church of Satan in 1966.