This particular book is based on a bit from the Old Testament.
Prince Hezekiah, of Juda, is living a rather boring princely life. He's the son of the King and his wife, the daughter of the (former) high priest of Yahweh. He gets schooled in Yahweh-ism by his high-priest granddad until the king becomes a vassal to Assyria (and its gods) and imprisons the grandfather (he was busy protesting the altar to the Assyrian gods at the Temple). King then gets his son a "good" tutor, who happens to be an atheist. King gets old and fat, tearing his kingdom apart to serve Assyria. Everyone turns away from Yahweh, cue indirect smiting. King dies. Hezekiah takes the throne. Comes back to Yahweh. Story ends and we are supposed to read what comes next as Hezekiah tries to bring his Kingdom back from ruins.
It would have rated an extra star or two if there had been a lot less Yahweh. There is a lot of bloat that's only about how awesome Yahweh is. Whatevs. My own fault, I know, reading something categorized as christian fiction, but I've read plenty of fiction whose plot was taken from the bible that was less preachy. I like less preachy. Getting too much into the whole god thing takes it to fantasy land, and there's better (and more fun) fantasy out there.