When men began to multiply on the face of the ground, and daughters were born to them, the sons of God saw that they were fair; and they took wives for themselves of all that they chose. Then the Lord said, "My spirit shall not abide in mortals forever, for they are flesh; their days shall be one hundred twenty years." The Nephilim were on the earth in those days--and also afterward--when the sons of God went in to the daughters of men, who bore children to them. These were the heroes that were of old, warriors of renown.
This passage has been a head-scratcher for Christians, but it need not be. I understand there are two opinions in the Church Fathers. The majority, though not the unanimity, suggest that the "children of men" are the offspring of Cain and the "sons of God" are the offspring of Seth, so that the mixing of the two lines corrupted the line of Seth. Another view, found in St. Justin Martyr, draws from the apocryphal 1 Enoch, which depicts the sons of God as fallen angels. St. Justin Martyr took it further and suggested that the Nephilim, children of these angels, were demons, who St. Justin identified with the Greco-Roman pantheon. A similar view appears in an embarrassing genre of Christian conspiracy sf (and sometimes nonfiction), which adds stuff about cloning, flying saucers, and the Great Pyramid. Sometimes it's fictionalized in other ways, as in Sci Fi's campy The Fallen Ones.
Now, why do I call this the mythological heart of the Bible? While studying Near Eastern archaeology at Toronto, and studying Catholicism, I arrived independently at the interpretation that appears in the footnotes of the New American Bible, which suggests that this passage gives place within the primordial history of Genesis for the stories of gods and heroes with which the original readers would have been familiar. First to my mind is Gilgamesh, son of the goddess Rimat-Ninsun and the folk hero Lugalbanda. His story, of course, includes a flood legend--and the Nephilim passage in Genesis is attached to a flood narrative also. In other words, the creation myth of Genesis doesn't reject the stories of other cultures, but gives them a place as well as a radical new interpretive framework: The gods who produced these children are rebels unworthy of worship. This is the spot in the Bible where all the great mythological stories go.
Now let's have your comments.