Another view sees
Genesis 6:1-4 merely summarizes that the sons and daughters of Adam and Eve had greatly increased, married and had children. It is an interlude before the narrative of the Flood. Therefore the sons of God were simply men.
Why Call The Sons Of God?
Why are they called sons of God and daughters of men? This summary description refers back to their origin. Though both were created in the image of God, each came initially from a difference source. Adam was directly created by God from the lifeless dust of the earth. Eve, however, was created from the living body of Adam. Therefore each descriptive term emphasizes their origin. Men are sons of God because this is where they have their origin. Women are daughters of man because their origin sprang from a man.
Therefore the sons of God choosing wives of the daughters of man is not necessarily a horrible act. This was the normal marrying and giving in marriage that Jesus spoke of that was going on before the Flood (
Matthew 24:38,
39).