During the last several decades of the 20th century, most public Satanists were only symbolic Satanists. That is, they did not literally believe in or worship Satan. Instead, they regarded Satan as only a symbol of various desirable qualities such as independence, individuality, and strength. Many were atheists.
From 1969 C.E. until very recently, most Satanists’ first exposure to Satanism was via Anton LaVey’s Satanic Bible. Hence, the vast majority of Satanists were LaVeyans or some fairly close variant thereof. However, beginning in the 1990’s, more and more people’s first exposure to Satanism has been via the Internet, allowing a wide variety of non-LaVeyan Satanisms to flourish – mostly theistic Satanisms, but also including some non-LaVey-based atheistic symbolic Satanisms as well.