Everyone knows the story of the devil, or at least they think they do. In the before-times, when creation was fresh and God was still putting the final details on the universe, one of his most powerful angels rebelled against him. The angel, known as Lucifer, was defeated, and cast into the pit. He's been there ever since, ruling in hell, and doing his best to corrupt the world his creator has attempted to turn into a peaceful place of love.
It sounds great, but if this myth has the familiar taste of a comic book origin story, that's because the whole idea of the devil as an outcast angel has a lot more to do with the influence of fiction authors like John Milton (the guy who wrote Paradise Lost) than it has to do with the actual source material. The Lucifer you think you know is a fiction, comprised mostly of an older, Canaanite myth, and some translation errors from the Old Testament.
Speaking of language problems, did you know there actually is a difference between devils and demons?
Also, for more biblical translation errors, you may want to examine the actual meaning behind the phrase thou shalt not suffer a witch to live.
Where The Word "Lucifer" Comes From
All right, let's begin at the beginning.
The word Lucifer appears in the Bible one time, in Isiah 14:12. The scene in question involves a spoken take-down of the King of Babylon, who had slighted the divine by refusing to acknowledge any power above himself. In this passage, the king (who is never specified, though may be one of the Babylonian kings from the line of Nebuchadnezzar) is referred to as a bearer of light, or the son of the morning, as a way to insult him by pointing out his overwhelming pride and arrogance. The term used was helel, which comes from the word halal, which means "to shine" in Arabic. When it came time to translate the concept from Arabic into English for the King James Bible (as one of the most commonly read versions of the text), the translators actually took the word Lucifer from the Jerome translation of the bible, called the Latin Vulgate.
The word, in that translation, referred to the planet Venus. The symbolism seems to be that Venus has come, filled the sky with its light, and it will soon be gone. Just as Babylon itself will be gone, fallen and ground to dust.
The Older Myths Some of This May Be Reflecting
The Old Testament wasn't written in a vacuum; the Israelites were surrounded, and affected, by the lands and cultures they lived near. One of those cultures was the Canaanites, who are mentioned several times throughout the Old Testament.
Bits and pieces of Canaanite myth and religion mixed into the Jewish faith, and clung tight. The god Ba'al, for example, was often worshiped as a lesser power by some of the Jewish people who lived in the desert. Ba'al was the king of the Canaanite gods, and he commanded the sun, and controlled the rain. Important things to have in your portfolio if you're going to be worshiped by people who live in the dry places of the world. In one of their myths, a lesser god named Attar attempted to ascend to Ba'al's throne, but found he was not as powerful as he believed, and instead descended into the underworld.
This isn't the only myth whose moral is, "you're not as powerful as you think you are." The myth of El and Helel, as well as the Greek myth of Phaethon have similar punchlines of "don't try to fill shoes that are too big for you."
So Where Did We Get This Idea From?
Mostly... because people thought it sounded cool?
The focus on the devil as constantly waiting around every bend and corner is a relatively modern thing. In the Bible, and particularly in the Old Testament, there were plenty of other issues to deal with that didn't involve the Adversary. From corrupt kings and backstabbing counselors, to traveling sorcerers, plagues, and wars, folks in these accounts had more than enough problems without getting the big-D's spaded tail involved.
As time moved on, though, biblical material fell into the hands of creatives. The devil has no origin story in the source material, and he's never once described in the book, so painters and authors just let their imaginations run free. Everyone loves a fallen hero, and by taking that idea, and sticking on pieces of stolen Greek gods and other pagan myths, we wound up with a figure whose story sold a lot of books, but is not backed up by much of anything in the Bible itself.