I thought Satan just was a misunderstanding. Armstrong spells it out in her, the History of God.
If I remember correctly. The root of the word is from erroneous worship. If you do it wrong you worship "Sheitan". So let's say God thinks suicide bombing really is wrong and you blow yourself up in gods name. Or even as something as simple as going to church on a Saturday. Then you're worshipping Satan.
So Satan isn't an actual entity or force. It's a misunderstanding, (on several levels). As far as I know it's only Catholicism who believe in Satan as a guy with horns. All the other Abrahamic sects have stuck with the original interpretation. So being corrupted by the devil isn't being talked into doing bad. It's just you being confused. Which is a much more beautiful world, isn't it?
It's also a very old term that is pre-pagan even.
edit: and reverting to the classic interpretation also evaporates a whole bag of theological paradoxes.