Taken from here: https://unveiling-christianity.net/2008/05/08/is-the-biblical-jesus-lucifer/
I’m sure you have heard Christians argue for Jesus’ divinity in light of “Before Abraham was, I am” (John 8:58). What they do is that they try to link this statement purportedly uttered by Jesus to that uttered by God in Exodus 3:14, “God said to Moses,”I am who I am”. This is what you are to say to the Israelites: ‘I am’ has sent me to you.’” I do not wish to get into a discussion and exegesis of these two verses. That is not the purpose of this article. What I will do in this case is apply “I agree with you for the sake of argument”. So let’s agree for a moment(for the sake of argument) that Jesus is God because he used the words “I am” which God used, that is, he equated himself with God. That is the logic which the Trinitarians use. Let us now apply the same logic with the following:
“King of Babylon, bright morning star, you have fallen from heaven! In the past you conquered nations, but now you have been thrown to the ground.”(Isaiah 14:12)
Everybody knows that the above is in reference to Lucifer. In fact, Lucifer means bright morning star, light-bearer, king of Babylon and Satan. Refer to the KJV Old Testament Hebrew Lexicon.
“I, Jesus, have sent my angel to give witness to you of these things in the churches. I am the root and the offspring of David, the bright and morning star.” (Revelations 22:16)
It is evident that “bright morning star” is an ascription used for Lucifer and in the above quotation we see Jesus using that same ascription for himself. So the conclusion is really quite simple. Jesus has equated himself with Lucifer. The Christians who equate Jesus with God by linking Exodus and John in the verses given earlier have no choice but to placate that Jesus is also the devil according to the Bible due to the verses in Isaiah and Revelations.
Jamieson-Fausset-Brown Bible Commentary on Isaiah 14:12
…. “day star.” A title truly belonging to Christ (Revelation 22:16), “the bright and morning star,” ……..