What does Isaiah 14:14 mean?

Here is the ultimate arrogance of humanity. On any human scale, the king of Babylon was far more powerful than other men. His word was law. He conquered one nation after another. He was feared by tens of thousands. For a time, he took whatever he wanted and made it his own. Human nature, though, is to never be satisfied. Having bested the world of men, Babylon's king set his ambition on the world of the gods. He believed in his heart he could make himself one of them. Not just one of the gods, he would make himself like the Most High. He did not see himself as just a mortal man.

The word for "Most High," Elyon, is usually used in the Bible to mean Yahweh, the God of Israel. Since the king's ambition seems to have been to sit on the sacred mountain of the Canaanite gods, he was likely referring to Baal (Isaiah 14:13). Isaiah will continue to mock just how far short of that goal the king has fallen.

Translation choices inspired the traditional belief that Lucifer (Isaiah 14:12) is a proper name for Satan, and that Isaiah's description also applies to the Devil's fall from heaven (Ezekiel 28:12–19; Luke 10:18; Revelation 12:7–9). Scripture offers truly little information about Satan, or why exactly he was cast out of God's presence. Some look to this verse as a motive: that Satan wanted to take God' place. This is possible, but Isaiah's real purpose here is to predict the ruin of Babylon.