Robert Wright makes an interesting argument:
Consider this innocent-sounding verse from the thirty-second chapter of Deuteronomy as rendered in the King James Version, published in 1611:
When the Most High divided to the nations their inheritance, when he separated the sons of Adam, he set the bounds of the people according to the number of the children of Israel.
For the Lord’s portion is his people; Jacob is the lot of his inheritance.
This verse, though a bit obscure, seems to say that God—called the “Most High” in one place and “the Lord” in another—somehow divided the world’s people into groups and then took an especially proprietary interest in one group, Jacob’s. But this interpretation rests on the assumption that “Most High” and “the Lord” do both refer to Yahweh. Do they?
The second term—“the Lord”—definitely does; this is the Bible’s standard rendering of the original Hebrew Yhwh. But might “Most High”—Elyon—refer to [the Canaanite god] El? It’s possible; the two words appear together—El Elyon—more than two dozen times in the Bible. What moves this prospect from possible toward probable is the strange story behind another part of this verse: the phrase “children of Israel.”
The King James edition got this phrase from the “Masoretic Text,” a Hebrew edition of the Bible that took shape in the early Middle Ages, more than a millennium after Deuteronomy was written. Where the Masoretic Text—the earliest extant Hebrew Bible—got it is a mystery. The phrase isn’t found in either of the two much earlier versions of the verse now available: a Hebrew version in the Dead Sea Scrolls and a Greek version in the Septuagint, a pre-Christian translation of the Hebrew Bible.
Why would some editor have invented the phrase? Was something being covered up?
Some scholars who have used the Dead Sea Scrolls and the Septuagint to reconstruct the authentic version of the verse say that “children of Israel” was stuck in as a replacement for “sons of El.” With that lost phrase restored, a verse that was cryptic suddenly makes sense: El—the most high god, Elyon—divided the world’s people into ethnic groups and gave one group to each of his sons. And Yahweh, one of those sons, was given the people of Jacob. Apparently at this point in Israelite history (and there’s no telling how long ago this story originated) Yahweh isn’t God, but just a god—and a son of God, one among many.
Wright’s intriguing book from which this excerpt is taken is called The Evolution of God.
And the book also discusses Muhammad’s own flirtation with polytheism.