In a straight reading of the first part of Genesis 6, verse 3 seems oddly placed. Verses 1 and 2 are beginning to tell about men multiplying on earth and the Sons of God taking wives of the daughters of men. Then comes verse 3, where God interjects that his spirit will not always strive with men. Verse 4 picks right back up with the narrative of the first verses. If we look at it chiastically, it makes more sense:
A. men began to multiply
B. daughters were born
C. Sons of God took daughters of men to wife
D. My spirit shall not always strive, days will be 120 years
C. giants in the earth; Sons of God came into daughters of men
B. daughters bore children
A. mighty men
God’s actions—removing his Spirit, ceasing to wrestle with man, and setting a countdown on the life of flesh—are the focal point of the passage, not just an aside awkwardly placed in the narrative. But this raises the question of what is going on that this is God’s answer? Who are the Sons of God and the daughters of men?
A place to start would be to note that chapter 6 comes after chapter 5 (how insightful! we shall see.) Chapter 5 outlines the lineage from Adam to Noah and his sons. Adam was made in the image and likeness of God; Seth was born in the image and likeness of Adam (who was made in the image and likeness of God). Enosh was born to Seth (in his image and likeness), and so on to Noah.
Let’s look a little closer at Seth. He was born after Cain murdered his brother Abel. His mother named him Seth—appointed, or set in place (of another)—because he was given by God in the place of Abel. Abel had been the one who walked with God, who would carry on the line of the Seed who would come to crush the serpent’s head.
This lineage is also set in contrast with the lineage of Cain at the end of chapter 4. These two genealogies are, I submit, the basis for understanding the Sons of God and the daughters of men in chapter 6. In other words, the Sons of God is not an idea or class that just pops into the narrative from nowhere, but should be understood in the light of the list of the sons made in the image and likeness of God given immediately before.
But what about the giants, the Nephilim? How could normal men and women have giant offspring? I’m not sure what more can be said except that the word Nephilim just doesn’t mean giants. It comes from the root nephal, which means to fall. These are the fallen ones, the sons of the line who strayed from walking with God, who fell into diverting, corrupting union with the ungodly. More on this presently.
With this understanding of the Sons of God, we can look again at God’s declaration in 6:3. God wrestles with men to bring them to maturity and glory. Jacob, as one of the clearest examples, became Israel—Prince-with-God—after wrestling with God and man and prevailing. Here God is giving them up, ceasing to wrestle. Giving them up to what? To their own lust and idolatry (which are perhaps the same thing). They are doing what the later Israelites did over and over. Numbers 25 is a good example. After Balaam could not curse Israel, he taught the Moabites to send out their pretty girls to entice the Hebrew men into taking them as wives and yoking themselves to the idol-gods of the Moabites (see Num. 31:15-16). The Sons of God were intermarrying with the line of Cain, the daughters of men, and were being led astray from following God; really, were ceasing to be sons and were becoming “mighty men”, tyrants like Nimrod who wanted to displace God, building a city and a tower with its head in the heavens, trying to make a name for himself rather than proclaiming the name of God.
Noah was the only uncorrupted man, the only one who walked uprightly in his whole generation. His father Lamech saw the corruption and lamented, but hoped that Noah would bring rest. The ark stood as a warning for how long? decades? They had had verbal warning through the prophet Enoch (see Jude 1:14-15), who named his son Methuselah—His-death-shall-bring-it. The flood is coming!
The Sons of God ignored it.
The flood came.