Genesis 6:1-2 (ESV emphasis mine):
When man began to multiply on the face of the land and daughters were born to them, the sons of God saw that the daughters of man were attractive. And they took as their wives any they chose.
Who are these "sons of God" (bene elohim) in Genesis 6:2? Are these some kind of divine being or angels that are intermarrying with human women? I've heard some people claim that they are the men in the godly line of Seth, while the daughters are from the line of Cain. What leads people to this interpretation? Are there other ideas?