Here is evidence that the idea of angels (sons of gods) impregnating women is pagan in origin. Ugarit was a city/kingdom in what is now northwestern Syria that worshiped the same gods as the Canaanites. Their writings mention Asherah, which is one of the Canaanite deities mentioned 40 times in the bible (H842 translated groves), and sons of gods. Ugaritic writings mention the 70 sons (gods) of Asherah mating with women to produce earthly rulers.
Claus Westermann claims that the text of Genesis 6 is based on an Ugaritic urtext.[11] In Ugaritic, a cognate phrase is bn 'il.[12] This may occur in the Ugaritic Baal Cycle.[13]
- KTU² 1.40 demonstrates the use of bn il to mean "sons of gods".[14]
- KTU² 1.65 (which may be a scribal exercise) uses bn il three times in succession: il bn il / dr bn il / mphrt bn il "El, the sons of gods, the circle of the sons of gods / the totality of the sons of gods."[12]
The phrase bn ilm ("sons of the gods") is also attested in Ugaritic texts,[15][16][17][18][19] as is the phrase phr bn ilm ("assembly of the sons of the gods").[20]
Elsewhere in the Ugarit corpus it is suggested that the bn ilm were the 70 sons of Asherah and El, who were the titulary deities of the people of the known world, and their "hieros gamos" marriage with the daughters of men gave rise to their rulers.[21]
Well, their demons did that.
The pagans just accepted it.