This is a common misconception.
Isaiah 14:3,4 "When the Lord has given you rest from your pain and turmoil and the hard service with which you were made to serve, 4 you will take up this taunt against the king of Babylon:"
The only verse which contains "lucifer"
Isaiah 14:12 "How art thou fallen from heaven, O Lucifer, son of the morning! how art thou cut down to the ground, which didst weaken the nations!"
This passage is not in reference to a fallen angle but an earthly king (the king of Babylon).
The word “lucifer” in the Vulgate is not a proper name. It is simply a translation from the Hebrew word “heylel” (or “halal” or “helel”), found in the Hebrew Masoretic text.
In the Book of Isaiah, chapter 14, the king of Babylon is condemned in a prophetic vision by the prophet Isaiah and is called הֵילֵל בֶּן-שָׁחַר (Helel ben Shachar, Hebrew for "shining one, son of the morning"). The title "Helel ben Shahar" refers to the planet Venus as the morning star, and that is how the Hebrew word is usually interpreted. The The Septuagint renders הֵילֵל in Greek as Ἑωσφόρος (heōsphoros), "bringer of dawn", the Ancient Greek name for the morning star. Similarly the Vulgate renders הֵילֵל in Latin as Lucifer, the name in that language for the morning star. The English translation given in the King James text is the Latin name for the planet Venus, "Lucifer"
The Bible translators translated the Hebrew word הֵילֵ֣ל or "helel" as “lucifer.” Helel comes from a root meaning “shining one.” However, Lucifer isn’t an English translation of the Hebrew word helel. It’s a Latin translation of the word. The KJV translators borrowed the word Lucifer from the Vulgate, the Latin translation of the Bible. In Latin Lucifer has the sense of “light-bearing” and “morning star.” Rather than translate the Hebrew word helel as “shining one” or “morning star” like modern translations do, the KJV translators inserted the Latin term “lucifer” and capitalized it in this verse. Since people thought this passage was referring to Satan, Lucifer became synonymous with Satan’s name.
Greek: ὁ ἑωσφόρος ὁ πρωὶ ἀνατέλλων | ho heōsphoros ho prōi anatellōn trans.: the Day Star, which used to rise early in the morning
Latin lucifer qui mane oriebaris trans: O Lucifer, who didst rise in the morning
The Devil's name is never mentioned in the Bible. Even in the book of Job, where our English translations call him Satan, that isn’t what we find in Hebrew. Satan is a translation of the Hebrew word “satan” which means adversary. In Job the word “satan” has “the” in front of it. It would be more accurate to translate each occurrence in Job as “the adversary.”
Names are important to God, a person’s name reflects their character. We see this when God changed the names of Abram to Abraham Genesis 17:4-6 and Jacob to Israel Genesis 32:29. To know someone's personal names makes it possible to cultivate a relationship with them, the Bible tell us to oppose the devil. God does not want us getting to know Satan the Devil. It stands to reason he wouldn't give us the personal name of a powerful spirit creature who is our proclaimed enemy, according to the Bible.
