The wiki article does a decent job. Basically the mentions of him in the texts describe different beings because they were written by different authors for different audiences with much different views. The serpent story has echos of other bronze age ones in that area and the text says as much that El put him there. The story in Job looks like a Cannite legend that got reimagined in Judaism. At some point the people of the region believed in desert spirits that would inhabit people causing them to go crazy and kill other people.

Due to the first exile Judaism started inventing an explanation for why they weren’t allowed to freely practice by imagining a being that was opposed to El. Because the pattern had broken. The pattern of the past was: everything fine, Jews sin, god punishs, jess repent, everything fine. However, this time they were trying to repent and weren’t able to. Which meant that something was blocking it. Hence Satan. The accuser.

By the time Paul came around the Book of Enoch was popular and to him Satan was a leader of a celestial army of angels. Which is why Paul said that had they known they were killing the son of God they still would have. That were not just following El. Off his writings we see things like Revelations and John where Greco-Roman celestial powers were merged with Satan and Lucifer together.

There was never an idea that someone had 2900 years ago and Christianity is following it. Like all myths it is a combination of different fables, attempts by people to explain their world, and thinkers continuing on a tradition.

I can’t comment on Lucifer and Satan but serpent reverence showed up in a lot of ancient matriarchal religions before they were displaced by modern patriarchal ones.

This doesn’t apply to only Abrahamic religions but shows up in Greek mythology too. Apollo slaying Gaia’s serpent messengers at the temple of Delphi for example.

Gnostic teachings, which are a form of Christianity, see the serpent as divine wisdom (Sophia) and the old testament God as the demiurge (Devil). Jesus as the good God. And Lucifer as the light of reason and not a villain.

But Gnosticism is basically a dead form of alternative Christian belief. So I have no idea what the modern church’s take is on these three entities.

I know that many of the modern misconceptions (according to Biblical canon anyway) about Hell came from Dante’s Inferno. So perhaps it’s also something like that?

Short of it is that the concept of Satan didn’t exist at the time Genesis was written.

https://www.biblicalarchaeology.org/daily/biblical-topics/bible-interpretation/how-the-serpent-in-the-garden-became-satan/

From a more literary perspective, there’s nothing that directly connects the serpent in the Garden of Eden, the interlocutor in Job, and the later mentions of Satan in the Hebrew and Greek scriptures (and there’s not a lot of direct mentions in the Hebrew scriptures). You can kinda make it work if you read between the lines, but fundamentalists will be the first to say you’re not supposed to read between the lines of the bible. To them, you take the word as it is written and nothing else.

Naturally, this rigid reading of the bible doesn’t work out so well for their beliefs.

To take the Answers in Genesis article on the subject (just because they’re a prominent fundamentalist organization), their reasoning is that the bible shows that Satan can enter into a physical being and control them. Notice that they leave out any reasoning showing that Satan did so in that particular case. He could have, and therefore, he did.