Also, Prince, he is the god of this world. It's the answer to the trick wuestion of "Who is the god of this world?". I mean, God is still in control - but Satan's motives and what he wants is blood smeared all over the picture.
I find the good thing, though, is the Devil must first seek permission if he can tempt a person. As you can read this in the book of Job, also there is another verse where the Devil asks God if he can do something.