In history many who are heavily influenced by Christianity and want to rebel, choose to worship the devil. They continue to believe Christian things, but, pick the Christian bad guy. That is devil worship, not Satanism. Satanism is complete different to Christianity and the philosophy surrounding the icon of Satan is not at all what Christians say it is. So, what is Satanism vis-à-vis devil worship?
“Entertaining though they might be, most stories and plays about Devil worship must be recognized as the obsolete absurdities they are.”
In case you haven't read any Satanic material before now, here is the basic declaration of The Satanic Bible:
“There is no heaven of glory bright, and no hell where sinners roast. Here and now is our day of torment! Here and now is our day of joy! Here and now is our opportunity! Choose ye this day, this hour, for no redeemer liveth!”
“Satanism is a ferocious religion based on materialism, the empowerment of the self and the ego, the carnal realities of animal life, the questioning of social taboos, the ridiculing of most other religions, and the promotion of tough social justice. Satan is not real but is the most ideal and accurate symbol of reality and nature: The world is full of violence, suffering, stress, striving and death - the life cycle itself requires all these things. It is clear that no symbol of 'goodness' or 'light' can embody it all. The vast, uninhabitable darkness of the Universe, with galactic cataclysms rendering huge destructions on huge scales, means that only Satan can embody the true state of everything that is. Satanists tend to use all the symbols of darkness and evil. There is no heaven, no hell, no afterlife, no angels or demons: there are no gods or saviours apart from ourselves. But if there was a god, it would surely be utterly evil.
The Church of Satan was founded in 1966 by Anton LaVey and as of 2001 its Black Pope has been the powerful and articulate Peter Gilmore. Satanism as religion is highly skeptical, rationalist and philosophical, demanding evidence and strong argumentation, but is otherwise open-minded on magic and some parts of the supernatural. Satanists are often bold, intelligent, demanding; but are also often subtle, cautious, hidden, while others still are outrageous, aggressive, angry and puzzling. It is a religion of fire, drama, depth and forceful progress.”
“As you can see there are no elements of devil worship in the Church of Satan. Such practices are looked upon as being Christian heresies. Believing in the Christian world-view of God vs. the Devil and choosing to side with the Prince of Darkness is pointless to the Satanist as neither exists. [...] To the Satanist, he is his own God. Satan is a symbol of Man living as his prideful, carnal nature dictates. Some Satanists extend this symbol to encompass the evolutionary "force" of entropy that permeates all of nature and provides the drive for survival and propagation inherent in all living things. To the Satanist, Satan is not a conscious entity to be worshipped, rather it is a name for the reservoir of power inside each human to be tapped at will.”
This involves people who worship The Devil, Lucifer, the Anti-God, The Dark Lord or Lord Satan or whoever. Often they talk of their preferred deity in the same way that Christians talk of their God, i.e., worship Him or die! Frequently Devil Worshippers require that you sell your soul to the devil in order to "be one of them".
If someone speaks in such ways then you're in ill company. Devil Worshippers make the types of noises which most people assume is in league with the Church of Satan simply because, with Christian heritage and bad horror movies suffusing the popular imagination in the West, it is easier to stick with Christian ideas than it is to research actual Satanism. Devil Worshippers are immature, unstable and nothing to do with the Church of Satan. Some groups of devil worshippers have survived decades but the vast majority implode into anarchy, and puberty, before they have time to settle.
Most the time these people cannot verify or decide who they are actually worshipping. They claim to love the AntiChrist. They are of course admiring characters from the Bible. If these people believe in the Bible it is clear that The Devil is not a God, but a fallen angel. How can you worship a mere angel, an inferior? So, as they do not believe in the Bible it must be a different Devil that they worship, but anyone can make up a God and pretend to worship it! Many Devil Worshippers are young and know nothing of the Bible so do not realize just how silly - and Christian - they are! Actively worshipping a being that is defined as bringing you ill fate is not something a fully-functioning mind does. A Satanist, instead, acts to improve his life, not to self-destruct!
It is just unfortunate that they often do not care to distinguish their Devil Worship from Satanism proper. They indiscriminately use the term "Satanists" despite the fact that their views blatantly contradict the Church of Satan. 'Satanism' as a word simply has a better ring to it than Devil Worshipper.
To explore in more general terms the type of theology that places Satan in a good light, read my page "Righteous Satan Theologies: When Satan is seen as Good" (2002):
“Some theologies and theories place Satan as a saviour and a defender of righteousness, and the white light God as an evil oppressor. Most common is the acceptance of Satan as true, a correct symbol used to represent crisp reality, with God as the negative symbol of delusion. Satanic religions hold to this idea even if they lack the actual belief in a real god or Satan. These are common themes in Satanic music, and are also present in nearly all schools of thought that are labelled as Devil Worship. Some ancient gnostic religions also hold that the good-seeming god is evil, whereas there are other more obscure good forces in life.”
Gilmore, Peter. High Priest of the Church of Satan (as of 2001+).
The Satanic Scriptures (2007). Hardback. Compendium of texts. Published by Scapegoat Publishing, USA. Many essays are new editions of older texts by Gilmore.