Now, if we look at the text of Isaiah 14 in context, and without the assumptions we brought to it from the New Testament, the meaning of the passage becomes more obvious and goes a radically different direction. The book of Isaiah has spent the first chapters denouncing the sins of Israel and its failure to be God’s people. There have also been expectations that God will work in new ways in the life of the nation to help them recover their mission as God’s people. One of those ways would be through a new king to replace the corrupt Ahaz. Because of his pro-Assyrian policies, the nation was teetering upon the brink of catastrophe as Assyria expanded to the West (see Assyrian Dominance).
Isaiah 13 begins a long section of the book known as "Oracles Against Foreign Nations." This is a standardized format in the prophets for universalizing responsibility to God. Not only Israel, but all nations, were accountable to God and would fall under the same judgment Israel would. As is typical in other prophetic books (Amos, Jeremiah, Ezekiel) not all of these oracles come from the same time period as Isaiah of Jerusalem, but they do follow a similar pattern and serve the same function in the book.
Isaiah 13 is part of the oracle directed against Babylon, probably from a time after the Exile. In very flowery, poetic, and highly figurative language, Babylon is denounced for her arrogance and lack of concern for other nations as she built her empire. It is interesting that in 13:10, specific mention is made of the failure of the Babylonian gods (constellations, sun, moon) to help them when God calls then to accountability.
Chapter 14 then begins with the promise of Israel’s return from Babylonian exile, a theme that dominates the middle section of Isaiah (40-55). Part of that return would involve the downfall of the tyrant king of Babylon (v. 4; probably Nebuchadrezzer; for the same language used of a later Babylonian ruler, Belshazzar, see Dan 5:20). In that context, verses 12-21 are a poetic picture of that downfall. Helel, morning star, and Shahar, dawn, then, are references to the Babylonian gods who could not save the king, and are themselves to be cast down. In fact, there is probably a reference here to the habit of ancient Near Eastern kings proclaiming themselves incarnations of the gods; with the fall of the kings, the gods also fell, often physically as the images that represented them were pulled down and destroyed (recall the symbolism of the overthrow of Saddam Hussein's statue in Baghdad).
So, the Isaiah passage does not connect, either historically or theologically, with the New Testament passages about the devil or the satan. By listening to the Old Testament passage on its own terms within its own context, we discover that Lucifer is not an Old Testament name for the devil or the satan. The passage in Isaiah 14:12-17 is directed at the downfall of the arrogant Babylonian rulers who took Israel into exile. By beginning with the New Testament, by making assumptions not supported by a closer examination of Scripture itself, and by using external theological categories as a lens through which to read Scripture, we may end up badly misreading Isaiah.