For those who have actually have actually read the Bible, surely they should be able to see the god depicted there is bonkers, unless they are wearing rose coloured specs!
Why do you continue to view the Bible as one book, just as the fundamentalists do? It's a library, with as many depictions of God as there are prophets. The worst depictions are in the Pentateuch, where probably the worst story of all occurs - that of Noah. Any idea how many times that story is referred to in the later prophets? Better still, any idea how many times the story of Adam and Eve is referred to in the later prophets?*
It's all just literature, some with a bit of historical fact (not much), lots of mythical stuff, some poetry, some moral advice (lots of it irrelevant twaddle about not worshiping 'false' gods). But all of it
changing, evolving ideas, and some of the early stories were probably completely unknown to quite a number of the later authors.
Satan, God - just ideas in people's heads, and all believers with different ideas about what these concepts might signify.
*My implication is that many of the writers in the Old Testament either didn't actually know these stories, or perhaps didn't consider them too relevant to the realities of their contemporary lives, since the references are so few.