Although many are dogmatic about it, we cannot know with complete assurance who the "Lucifer" in this passage is. Certainly he is not Jesus, but whether he is Satan or the king of Babylon (or both) is not clear. We must keep in mind that the OT prophetic books often mock the grandiose claims of earthly kings as a kind of satire on their desire to be god-like. This passage could fit into that category. Also, the word "Lucifer" is Latin and comes into the KJV from the Vulgate. It was not the word originally used by Isaiah. If the passage refers to Satan, then perhaps his name was "Helel" (Hebrew for "light-bringer"), not Lucifer. I'm not denying that Satan is pictured here, only that we must allow for other interpretations.