EVIL ANGELS, THE NEPHILIM, AND THE BOOK OF ENOCH are discussed by Tim Townsend in the St. Louis stltoday.com website:
Evil, from the backs of fallen angels
BY TIM TOWNSEND • ttownsend@post-dispatch.com > 314-340-8221 | Posted: Saturday, December 10, 2011 12:10 am | (9) Comments
Among what scholars have traditionally thought of as the strangest passages in the Hebrew Bible are four verses toward the beginning of Genesis about evil angels.
It's a short story, written 2,500 years ago, with roots that go back even further to Hurrian and Canaanite mythology. In these verses, angels that the author calls 'sons of God" came to earth and mated with human women, producing a race of demi-god giants called the Nephilim who roamed the earth until they were wiped out with the rest of humanity in The Flood.
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A pretty good popular discussion, but I do have one comment:
The author of The Book of Enoch, written in the third century B.C., amplified the Nephilim story, and the angels not only mate with human women, but share with them secrets about warfare and other "knowledge they would have been better off not knowing," said Susan Garrett, professor of New Testament at Louisville Presbyterian Theological Seminary, and author of "No Ordinary Angel." In the Book of Jubilees, written in about 150 B.C., evil spirits rise from the bodies of the dead Nephilim and invade the earth.
I would say that the Nephilim story in Genesis reluctantly summarizes the story of the fall of the Watchers (the angels), a version of which story is also found in the Book of the Watchers in
1 Enoch. Some specialists would disagree with me on this, but I can't see any other way to read the development of the legend.
1 Enoch is not amplifying (or not much); Genesis is summarizing and bowdlerizing.