Satanism represents various religions and philosophies that focus on the figure of Satan in Abrahamic religions as a source of personal, metaphoric, or magical inspiration. Satanism is part of the practice of the Left-Hand Path. The ideals of Satanism are a focus on autonomy, knowledge, self-expression, and fulfillment of desire.
In terms of theology, Satanists today can be divided into two main groups:
- atheistic Satanism does not believe that "Satan" actually exists, as such, they do not worship Satan. They believe every person is their own god and that everyone should worship themselves. To them, "Satan" is just a symbol of rebellion. The most well-known example of this group is Anton LaVey, founder of the Church of Satan.
- theistic Satanism believes that "Satan" is an actual independently existing being, whom they worship and serve as their god. This is highly uncommon and not in accordance with the teachings of Mr. LaVey.
- some deny God's existence
- some believe that God exists, but is weaker than Satan
- some believe that God exists, and that Satan is weaker and God will ultimately triumph over him - and even, they will be consigned along with Satan to an eternity in hell. But, they believe, "Better to reign in Hell than serve in Heaven", as Milton said.
Another more sociological division of Satanists:
- organized Satanism - these are organized, publicly known Satanic groups. They publicly oppose criminal activity, and have well-developed theologies which they often publish electronically or in printed form
- dabbler Satanism - teenagers who turn to Satanism as a form of rebellion against their parents, school, church, etc. Generally they lack a well-developed theology. Often are involved in petty crimes such as vandalism, although occasionally have been linked to more serious criminal activity. Most of them grow out of their Satanism, although some will develop into another form of Satanism over time.
- 'sicko' Satanism - criminals, psychopathic individuals, that use Satanism as a justification for criminal activities such as murder, rape, child molestation, etc. Generally lack a developed theology. In some cases the trappings of Satanism are used to try to scare victims (especially children) into not coming forward. Most commonly are loners, or occasionally small groups
- 'showbiz' Satanism - musical and other groups who use the trappings of Satanism for artistic purposes. Sometimes this is meant seriously (e.g. the musician is an adherent of organized Satanism, and sees their art as a vehicle for spreading Satanic ideas.) In other cases, Satanism is not adopted as a belief system but rather chosen to be shocking or outrageous, or due to an artistic preference for 'dark' imagery
- conspiratorial Satanism - large scale, conspiratorial groups which practice human sacrifice, child molestation, etc., many of whose members allegedly occupy positions of power, authority or respect in their communities, such as doctors, lawyers, politicians, police officers, schoolteachers, etc. It is controversial whether any of these groups actually exist - many therapists believe they have treated patients who survived these groups, and individuals have come forward with testimonies of their time in them. But others view these groups as mythical (a "Satanic panic"), and believe that claims to have survived them have actually been induced by the therapists
Satanism became a socially recognized phenomenon with the advent of The Satanic Bible  and The Church of Satan. Prior to this, concepts or ideas of Satanism were used as religious propaganda by the church for witch hunts. The only evidence for the existence of organized Satanism in history is found in the 20th century.
The Satanic Bible contains the core philosophy of LaVey Satanism. the concepts were based on the philosophies of Nietzsche and "The Will to Power" and Ayn Rand "Atlas Shrugged". Rumors that these ideas are plagiarized are unfounded because the complete Bibliography for The Satanic Bible was printed in earlier versions of the book. The Satanic Bible is the core document for many Satanists. The philosophy of LaVeyan Satanism is based on objectivism, humanism, and rationalism.
The majority of LaVey Satanists are atheist and they see Satan as a symbolic metaphor for life and nature. The method of Magic promoted by the Church of Satan is psychological and primarily non-esoteric. Most members of the Church of Satan do not accept the existence of an afterlife. The current High Priest of the Church of Satan is Peter Gilmore.
There are other groups which came from this social phenomenon created by LaVey. The initiatory organization known as the Temple of Set was created in 1975 by Lt. Colonel of the US Army Michael Aquino and other members of the Church of Satan who left after a disagreement in policy. The Temple of Set is a legally recognized non-profit church.
The religious documents that form the foundation for the beliefs dogma and practices of the temple of set are the Crystal Tablet of Set. They are primarily theistic and their view is that Set is a manifestation of Satan. The teachings of the Temple of Set focus on enlightened individualism which is the development of self in positive and beneficial ways. This is known to the Temple members as Xeper (compare, Thelema) The office of High Priest is currently held by Magistra Patricia Hardy, who succeeded Aquino in 2004.
Independent Satanism is an eclectic form of Satanism that focuses on individualism and self enlightenment without the aide of group or organized Satanism. many are self-initiated into the practice of Satanism and are known as solitary practitioners of magic. The method of independent Satanism include the signing of a pact or agreement with their chosen Satanic deity. Independent Satanism can take on a variety of beliefs from different sources, and they tend to develop their own personal life philosophy independent of popular Satanic thought.
Theistic Satanism is often classified as Satanic worship, the worship of the Christian Satan. While some practice this form of Satanic Christianity, other Theistic Satanists choose to see Satan as one of many gods, and may not choose to include worship as a part of their personal spirituality. Theistic Satanists may practice a form of Satanic Henotheism, which is the dedication to Satan while including other gods into their personal pantheon.
Christian Satanism, sometimes labeled as Traditional Satanism, combines elements of Christianity with Satanic myth and religion. The Traditional Satanist philosophy may include the belief in Satan as a creator god, or Satan as the enemy of the Christian God. Traditional Satanists also tend to believe in the existence of the afterlife. Some Traditional Satanists use the Al-Jilwah as a religious document based on the belief that the Al-Jilwah is the revealed word of Satan.