We know that Satan for a time was the guy who did god"s dirty work. He obtained permission from God,did nasty things for God,but did he really have any power or " magic" at his disposal other than that God granted him?
Theists can you please explain where Satan,as a fallen angel,separates himself from God but still retains his "supernatural" powers,enough to dispose of God as an influence over peoples of the earth?
The only way Satan can still have supernatural powers is if God gives it to him as a reward for his service.
To the best of my knowledge, there is nothing in the Hebrew Bible (aka the Old Testament) or the New Testament that specifically explains the origins or the fall of the Satan.
Granted, there is Ezekiel 28:12-18 which allegedly explains the fall of the Satan. Oddly, when I have asked various literalists about why this particular passage is symbolic but all the other writings before and after it are to be taken literally, I get a quiet "I don't know".
In the Hebrew Bible the Satan (which translates as "accuser") was essentially a prosecuting attorney, finding wrongdoers in the world and bringing them to God's attention. The Satan seems to have had a rather large ego as described in the book of Job but that is a speculation on my part.
There is a theory that the Satan morphed from God's D.A. to this source of evil during the Babylonian captivity of the Southern Kingdom. When the Persians conquered the Babylonians they also brought a belief the world was a battle ground between a force of good and a force of evil. The Jewish leaders were exposed to this and liked it as it helped explain why they, as God's chosen people, were conquered and transplanted to Babylon.
Because the Persians were more tolerant of alternate religions (provided they paid their required tribute to Babylon) there was an exodus of sorts of Jewish people back to Israel. The theory says they brought this understanding of a force of evil in conflict with God with them back to Israel. There is a 300 year gap between their return and the time of Jesus the Christ.
There was probably a lot of writing going on but precious little has been found. But by the time of Jesus the Christ, the image of the Satan as a force of evil appears to be fairly strong and well known as the New Testament writers don't offer anything explaining origins of the Satan or the fall of the Satan.
Most people understand the fall of the Satan from Bunyan's book "Pilgrim's Progress".
Here is some additional information you might find of interest. http://en.wikipedia.org/wiki/Satan
End of lecture.