Satan is an idea. Satan is NOT the entity so commonly reffered to as the devil. The Christians made sure you would always associate satan as being the devil to move their own agenda forward. Satan is any idea that goes against the status quo. When following the little trail of meaning, the word satan comes to simply mean "opposition."
So let's get it perfectly clear: satan==any idea from any man that poses a threat against the majority's brainwashed way of life. devil==the "scary" horned demon guy that supposedly is the king of all evil in a burning existence underneath us all.
Everyone always confuses the devil with satan.
Which makes more sense to you? Thought so.