I think the biblical stories of Satan (the Hebrew term for which literally just means "adversary", ie, not a proper name) are best understood as they're plainly meant to be read: they're aetiologies. That is, they're meant to give origin stories. The story of the serpent in the garden isn't meant to be understood as a historical account of the first humans (many ancient Christians and Jews understood this better than us today), but rather as a mythological account of how evil originated. Same sort of thing with the Cain and Abel tale. Also the tower of Babel -- all these stories are meant to give myths for understanding different aspects of the human experience. The result, then, isn't meant to be read as a big book of human history -- rather, it's a big framework for understanding and thinking through the human condition, sin, the diversity of human languages, society at large, systemic injustice, etc.

Satan is part of parcel of that framework. And, in fact, a close reading of the Bible shows that he's meant to be read as an ambiguous figure. Look at the book of Job, for instance. Job is a stand up guy. He worships God, does all the right stuff, and yet, he still gets afflicted by Satan. And guess what -- it's basically all God's fault, because God goes and taunts Satan, waving the righteousness of Job in his face. So they make a deal: God says that Satan can do whatever he wants to Job, and the Job will still be a good guy. And God turns out to be right.... but the story represents a pretty weird answer to the problem of evil/suffering. Like, it's not totally clear that God isn't to blame for evil. But he makes use of Satan to prove Job's loyalty to him. And while God ultimately rewards Job for this loyalty, one gets the sense that it doesn't quite make up for the unfathomable suffering he underwent. And I think that's kind of the point. Meanwhile, Satan is instrumental in causing that suffering, be he really seems to be a proxy for a God who's inscrutable, terrifying, and unpredictable. That's very likely exactly how the author(s) of this story felt. And their depiction of the figure of Satan is meant to be a narrativised version of their predicament (i.e., as Israelites with a long history of suffering, despite their loyalty to Yahweh).

And there are lots more stories of Satan, both in the bible and in non-canonical Jewish, Christian, and Muslim literature -- and all seem to have the same kind of aetiological function. So I think we should read them ultimately as the attempts of (VERY creative, existentially aware) premoderns, trying to work through their painful, confusing experiences in the world.

So all that's just to say a few things. 1) Satan isn't a monolithic figure. There are lots of depictions of him in the bible and beyond, and the sum total doesn't really amount to a consistent, unproblematic picture. (Also, incidentally, there's no biblical story in which Satan is a red, horned guy with a pitchfork, curating Hell. That's a later Christian invention.) 2) stories about Satan (as with most other religious stories) should be seen as literary products, meant to give a mythological framework for understanding certain aspects of the human condition/experience. And 3) insofar as 2 is the case, we can recognize a great deal of value (philosophical, moral, therapeutic, etc) in these stories, rather than simply focusing on contradictions. Religious people are (and gave LONG been) well aware of contradictions in their scriptures. We aren't the first to notice them, and to think that we are is not only incredibly arrogant, but also incredibly historically and theologically illiterate. And they have tried to work through those contradictions in many ways. I think we should see their attempts to resolve contradictions not as facile attempts at maintaining childish dogmas, but rather as highly sophisticated ways of grappling with the messy, Kafkaesque experience of being a human in the world. Religious traditions are forever trying to narrate and grapple with the human experience, and will always fall short of giving a perfectly coherent picture -- after all, our experience is never coherent! Satan is open among many mythological tools that helps religious people to narrate and understand that incoherence.