The Origin of Satan by Elaine Pagels (1995): Pagels adapts some of her scholarly material on the social dynamics of early Christianity into a book for laypersons, with admirable results. The origins recounted here are not of the mythological variety; rather, Pagels explores the human and social origins of Satan in particular and demons in general.
Part of this exploration must go into the Old Testament, in which “the satan” was an angel of the Lord tasked with putting obstacles in the path of a good person who was straying. The Book of Job and subsequent works gradually altered this dynamic, making the satan — or perhaps just Satan — into an angel who tests the faithful. But it wouldn’t be until the development of various first-century cults, and ultimately Christianity, that an actual independent Adversary of God would arise.
Pagels clearly explains, develops, and supports her argument as we move through the synoptic Gospels and other early books of the New Testament. Christianity tended to demonize its early opponents, first the Jews and then heretical components of early Christianity, especially those with Gnostic tendencies.
The demonization of the Jews in Matthew, Mark, Luke, and John increases as a component of how long after Christ’s life they were written; the guilt of the Roman authorities decreases along the same timeline, until Pilate — historically a real bastard of a Prefect, even for Roman Prefects — has become an ineffectual man who sought to save Jesus, a portrayal that seems extraordinarily unlikely given the non-Biblical historical record’s evidence both of how the Roman Empire worked and how Pilate himself governed.
And by demonize, Pagels means to literally demonize — religious opponents of Christianity were the servants, pawns, and possessed creatures of the newly posited cosmic evil of Satan and his angels; the universe itself was a battleground for actual demonic forces and the forces of Good, though one where the battle was already won by Christ’s sacrifice on the cross. Even the word ‘demon’ was a demonization of the Latinized Greek term for non-human spirits who were not necessarily good or evil.
All in all, clearly written and extremely informative. As noted, this is not a mythological exploration per se, but instead a sociological and social one with applications that range far beyond early Christianity through the discussion of how particular religions construct the face of the enemy, and make ‘it’ inhuman. Satan is as much human as angel. Highly recommended.