Interesting link.
This line from the site sums up their satanic faith:
"Do what thou wilt shall be the whole of the Law."
It's all about service to the self, above others at all costs. Reminds me of Ayn Rand, who claimed to be an 'atheist' but really was a satanist. Many of them claim to be atheists but they worship their god. They just reject their father and creator the Almighty God, in favor of satan.