The Temple of Set was founded by LaVey’s former right-hand man Michael Aquino, who left the Church of Satan after LaVey had started to sell priesthood offices. The idea that LaVey would profit from the Church of Satan caused many members, including high priestess Lilith Sinclair, who eventually became Aquino’s wife, to resign from the church. Aquino and other defectors helped form the Temple of Set, which developed very different philosophies from the Church of Satan.
While LaVeyan Satanists don’t believe in any sort of god or deity, Setians “believe” in a suprapersonal entity known as Set. Set is the Egyptian god of violence and disorder, who eventually became known as the god of darkness and the enemy of all other Egyptian gods. In other words, Set is “the original Satanist: the ‘god’ against all false, man-imagined gods.”
LaVeyan Satanists believe that each member is their own personal god, and they seek to ascend to godhood. The goal of Setians is to achieve xeper, an Egyptian word that roughly means “I have come into being.” Setians believe that each person goes through a divine experience at some point or another and that it is possible to create more divine experiences through self-development, magic, and other means until the Setian finally achieves a level of godhood. This is the ultimate purpose of man.