1 And it came to pass, when men began to multiply on the face of the earth, and daughters were born unto them,
2 That the sons of God saw the daughters of men that they were fair; and they took them wives of all which they chose.
3 And the Lord said, My spirit shall not always strive with man, for that he also is flesh: yet his days shall be an hundred and twenty years.
4 There were giants in the earth in those days; and also after that, when the sons of God came in unto the daughters of men, and they bare children to them, the same became mighty men which were of old, men of renown.
5 And God saw that the wickedness of man was great in the earth, and that every imagination of the thoughts of his heart was only evil continually.
6 And it repented the Lord that he had made man on the earth, and it grieved him at his heart.
Theory 1 – Nephilim as Offspring of Fallen Angels and Human Women
The view that has increased in favor today is that the Nephilim were offspring of fallen angels and human women has increased in favor today is the position that the “sons of God” were fallen angels who had relations with the “daughters of men” (Genesis 6:1-6), and as a result, the Nephilim were born. This is the most popular view in the Church today.
Support for the theory. A verse that supporters of this position turn to is Job 1:6 “Now there was a day when the sons of God came to present themselves before the Lord, and Satan also came among them.”
In connection to this verse Job 38:6-7 also tells us “when the morning stars sang together and all the sons of God shouted for joy?”
These verses use the same term found in Genesis 6. Theologians historically have interpreted the “sons of God” as “angels,” which fit right into the context of these verses. One main Scripture passage used to defend this view is Jude 1:6-7.
And the angels who did not keep their proper domain, but left their own abode, he has reserved in everlasting chains under darkness for the judgment of the great day; as Sodom and Gomorrah, and the cities around them in a similar manner to these, having given themselves over to sexual immorality and gone after strange flesh, are set forth as an example, suffering the vengeance of eternal fire.”
The Jude 1:6-7 passage indicates there were angels that went after strange flesh.