A satanist is an adherent of Satan. Satan is considered diabolical and not all of us are full of wickedness. You may say we all have a bit of Satan in us, but there are some who don't.

The purpose of life is to get what you want with minimal effort. That's why we've evolved. If you can do one task, up to par, with minimal effort, you can accomplish another task at the same time, and soon, you've evolved into a multi-tasked individual. I want to be able to run across the city with minimal effort. Not because I'm lazy, but because then I'll have more energy to do other things once I get there. Too be able to do that, I'd have to use mostly mental power to get me there, seeing how I'd probably get tired. Then my Brain would have further evolved because it controlled my fatigue. Either way, Satanism is just a way to denounce Christianity. That's how Satanism started and it wasn't until about 1200 years after Jesus Christ.