Something that gets glossed over a lot, sort of like missing the forest because all those trees are in the way, is that Islam and Christianity are siblings. The offshoots and latter Abrahamic religions that came after Judaism, the mythology of the faiths and many of the beliefs and practices are the same or quite similar. Of course due to the language barrier it sometimes gets confused. And while individual parts of the mythology might change, there are definite marks of relationship. Take the story of Iblis, who is for all intents and purposes the devil of Islam.
There are a few different version of this particular fall from grace, so let’s start with the big one. Before the creation of man there were the race of djinn. Djinn (what we now think of as genies) were heinously powerful creatures of spirit who could not be damaged except by magic or divine power, who could change their shape and who lived long enough they were thought to be immortal by many. God sent his angels to destroy the djinn, and though most were killed there was one, named Iblis, who was thought to show great potential. A being of fire, an ifrit, Iblis was taken to heaven and educated there. In time he became devout, and he preached the word of the Lord to the angels. When God made man though, and commanded all bow down to him Iblis refused. Some say this was because he was fire, and thus greater than a creature of dust, but others say that Iblis would bow only to God. Whatever the reason, Iblis was cast out of heaven, where he became a king of the djinn who had rebuilt their own nation. As king he and his djinn traveled the world to tempt man into sin and to commit great evil. More on that later.
There are other versions of this myth, but they get confusing. One is that Iblis was in fact an angel, a leader of those who fought the djinn called Azazel. Upon returning from his campaigns he found that God had made man, and the victorious leader of the heavenly host would not lower his head to a newly created thing of dust. At this point Azazel was somehow transformed into the djinn Iblis and cast out where he became a king among those he used to fight. There are also passages in the non-canonical books of the Bible that refer to Azazel being on the of the creators of the Nephilim. This gets confusing, because Iblis is not supposed to have divine heritage according to Islam, but it’s another version of the creation of evil.
Speaking of evil, Iblis has a big load on his shoulders. A powerful spirit, Iblis was given a stay of execution until Armageddon. Until that time he and his djinn were to roam the world and tempt others into straying from the path of righteousness and turning their backs on God. Iblis could cajore and offer, but he could not force actions except through possession, which was a sure method to give yourself away because those who committed horrible actions were said to be possessed by a demon. The djinn, some of whom were considered ghouls, could also possess the bodies of the dead that hadn’t been dedicated to God to create zombie-like creatures that could commit great acts of wickedness.
In either form, Iblis or Azazel, this being was said to dwell in the desert wastes. Places where God was said not to be, and thus the haunt of the djinn who could flourish there. However, it was said that djinn that took human form could follow Islam and become righteous in their ways. Not all were cursed to be as Iblis was, a Shaitain or al-Sharain which means “enemy of God.” The idea that the word Satan didn’t refer to a single being, a Lucifer-like cast away (leaving aside the contention that the word Lucifer is a misranslation), but rather to the rebel and all of his forces is one that might be able to explain how all of the wickedness in the world could be laid at the feet of a single force. Especially if that force wasn’t strong enough to win against angels or god, but it is lead by one who is acting in the role of tempter becase that is the role he was given.
“Iblis,” by Anonymous at UVIC
“Iblis,” by Alan G. Hefner at Pantheon
“Iblis,” by Anonymous at Djinn Universe