Although Bible Artists can expect that modern audiences will know the basic outline of the Babyl story, awareness of the supernatural/cosmic effects of this story is far less common. In part, this is because our knowledge of the supernatural implications of Babyl comes not primarily through Genesis 11 but rather through Deuteronomy 32:8-9:
When the Most High gave to the nations their inheritance, when he divided mankind, he fixed the borders of the peoples according to the number of the sons of God.
But the Lord's portion is his people, Jacob his allotted heritage. (ESV)
Moses here allusively suggests that the division of the nations (which Genesis 11 makes clear happened in wake of Babyl) resulted in God giving each of the "sons of god" (spiritual beings other than Yahweh) dominion over one of the nations listed in the Genesis 10 genealogies. This provided the ancient Israelites with a way of understanding why the other nations had gods other than Yahweh. Unlike us moderns, they didn't view rival pantheons as superstitious nonsense; rather, they looked at these other spiritual beings as Yahweh's spiritual subordinates, who had rebelled and driven their nations into sin (cf. Psalm 82). Dr. Michael Heiser refers to the ideas here as "the Deuteronomy 32 Worldview" and provides an in depth exploration of them through his book, The Unseen Realm, as well as the Naked Bible Podcast.
This background is quite interesting to study, but the question for Bible Artists is, how much should actually make its way into an adaptation?
Approaches to the Spiritual Dimension of Babyl
1) Avoid It
Heiser doesn't refer to spiritual beings as "the unseen realm" for nothing. The Bible very rarely depicts the actions of spiritual beings (other than Yahweh) in a direct way, and the Genesis 11 follows this trend. Although an intriguing layer of significance is lost by omitting any mention of the sons of God and the spiritual ripples of Babyl, the story is still quite coherent if these forces are never mentioned directly. Indeed, because we have only allusive data about the role of spiritual powers during and after the Babyl event, it's difficult even to picture how one would directly integrate them into a dramatic adaptation.
2) Frame Narrative
If you've been reading along in this Adapting Genesis series, you've probably started to recognize my appreciation for frame narratives as a storytelling device. This kind of content seems like a perfect example of the kind of thing that would be difficult to depict directly onscreen and could much more easily be introduced through exposition by a narrator. Indeed, the fact that the Genesis 11 narrative doesn't focus on the spiritual realm but leaves that aspect of the story for other passages to bring out via commentary may be instructive for how adaptations should handle that layer of the story themselves.
Because the Babyl story is framed as an etiology, it doesn't take much imagination to picture an appropriate frame for it. A young Israelite (whether in the time of Moses, thinking about Egypt & the Canaanite nations or in the time of the Exile, thinking about Babylon specifically) asks the question I alluded to earlier: why are there nations with gods other than Yahweh? The Babyl story can be told by the narrator (a priest or prophet), who then provides an additional explanation of what was going on behind the scenes in the spiritual realm. This puts the film's characters in a similar position to modern audiences with regard to the spiritual world: unable to see it directly but quite aware of its ongoing effects.
3) "Prophecy" & Possession
CS Lewis' That Hideous Strength takes elements of the Babyl Story and transplants them into a more modern context. In doing so, it provides an alternative model for how to depict the role of the powers of darkness - one that is slightly more direct, without being too over-the-top. THS explores a Babyl-like human initiative (NICE) from within, by following an ambitious but not-irredeemable member, Mark, as he goes from being a nobody to an insider. Initially, Mark's time at NICE is spent interacting with human bureaucrats. Some of their ideas and behaviors are bizarre, even disturbing, but their evil is a very human kind of evil, driven by pride, ambition, and envy. As Mark works his way further and further into the heart of the organization, however, he eventually discovers that the insiders of the insiders are possessed by a much more sinister and supernatural form of evil. Fortunately for him, when he resists their temptation, a very Babyl-like divine intervention ends up saving him - and the world - from the ways that these spiritual powers are manipulating the world through their human puppets.
A THS-like approach for the Babyl story would work best if we are following a character who, like Mark, is a Babylonian insider. From the perspective of outsiders, the efforts of Babylon are a very human evil - ambition, pride, and self-exaltation. Only an insider, passing through the ranks of Babylonian society, would ever interact with extra-human influences, and, even then, may only do so indirectly through a possessed "prophet." Based on the main character approaches that we've already explored, this sort of scenario seems fitted best to a story that follows Nimrod's rise to power. Unlike Mark, however, he would fail to resist the influence of the Powers and would end up bringing about their destructive purposes on his own head.