I would classify myself as an Agnostic Atheist. So, no. I don't believe in God. Nor do I believe in Satan.

It's my feeling that religion was created as a method for the strong to maintain control over the weak, by threatening the wrath of a diety if they did not obey.

As a result of this, I just can't bring myself to believe in any higher power. I live by my own set of morals, which I may add are much better than the morals (or lack thereof) of some people I know directly involved in my life (I.E. my supervisor, who touts himself off to be a good Christian, but in reality has absolutely no integrity, no moral fibre, and is the biggest hypocrite I've ever met in my life.)