Hey. Preface. I am not a Satanist, and really know nothing of your practices other than most of your general laws and regulations are cool. With that in mind, please understand that I was raised Catholic, am now a Hellenistic Pagan, and do most of my research on the limited cool websites that I actually know exist.
Onto the point.
I began my research because of a literary project. And because I was living with a 'Christian' at the time and wanted to prove to them how little they knew of their faith. In any case, here is what I found, for those of you who could use this information.
Lucifer was originally a latin word. There are *so* many early saints named Lucifer it's ridiculous. It meant light-bringing, morning light, and only exists in the Latin manuscripts of the Christian Bible once, in Isaiah 14:12. It is most commonly believed by scholars to refer to Nebuchadnezzar II, in biblical reference.
However, in most other scholarly texts, the term "morning star" refers to Venus, thus explaining Lucifer's general charisma in literature. He's the most beautiful of the archangels, as my Spanish Catholic Devotee great-grandmother explained to me when I was very young.
It's very late here however so if anyone wants to comment on this or correct what I have that is wrong, please do feel free to do so.
Satan comes from the Hebrew word for Adversary. In the Book of Job, Satan is the adversary of Man, not the adversary of YHWH. After Christianity became mainstream, the legend of Satan became analogous to Prometheus in order to appeal to the Greeks. I believe that's why Lucifer became another common name for Satan; he brought the Light of Wisdom upon Man the same way Prometheus brought fire. He is our Adversary out of a way of education, not out of malice.
If you get rid all the Christian text and travel back where there was no Satan or anything dscribe in bibles Ishtar/Inanna was tittled morning and evening star. The belief system was a complex but where they would get most the ideas from and prototype of Lucifer.