We can trace the story of the nephilim throughout various parts of the Bible. From the nephilim and their interaction with God’s people, we can learn to recognise the typical conflict between God’s ways and man’s ways, and the result that occurs when following one versus the other.
Keeping with the many scriptural references to “sons of God” being those who are believers (cp. Gal. 4:6, 3:26, Rom. 9:26, Rom. 8:14, 19), I am left to conclude that Genesis 6 is building a contrast between believers (the “sons of God”) and non-believers (the “daughters of men”). Once we connect these dots, the story of the nephilim, and the lessons we can learn from them, begins to take new shape:
Consider, for example, the negative comparison Jesus makes in Matt. 24:37-38 (also Luke 17:26-27) between the time of the “coming of the Son of Man” and “the days of Noah”. The reference to giving and taking in marriage and “the days of Noah” would appear to be a reference to Gen 6:2&4 (where nephilim are mentioned). In Matt. 24, Jesus isn’t suggesting that there is a problem with marriage, as marriage comes from God (Gen. 2:18-25). What his problem seems to be when he is referring to the state of his day is that the motivation for joining in marriage between people is beauty or appearance, not believing or faith, and that is indeed problematic.
One of the messages that God reveals to us, then, through the story of the nephilim is about the right (and wrong) basis for relationships; through the story of the nephilim he begins to make his point about alliances and reliances and what works in a relationship versus what actually doesn’t.
Consider also the following chain of verses about the nephilim: Num. 13:33 (the descendants of Nephilim), Josh. 11:22 (the last remaining homes of the Anakites who had nephilim) and 1 Sam. 17:4 (Goliath comes from Gath, the home of the remaining nephilim). We are told that the Anakites, and, therefore, the nephilim, were descended from Arba; and then we see the systematic removal of the Anakites from the land until, finally, we have a show down between David and Goliath.
Goliath appears to be a descendant of Arba and therefore a nephilim (a “giant” or “mighty person”) who becomes a champion for those who would dare to fight against the “armies of the living God” (to quote David [1 Sam. 17:26]) and David, who is clearly a champion and representative of those who will follow and stand for God — it’s like the “sons of God” versus the “daughters/sons of men”, again.
So a couple of different messages come to us from the account of the mixed nonbeliever-believer marriages in Gen 6. First, the result of pursuing marriage outside of the faith may appear to have good results, but anything that begins with man providing for himself is ultimately going to have unexpected, negative ramifications. In this case, the offspring who come from the marriage are mighty, but they end up relying on their own abilities and strengths and, ultimately, in opposition to God.
The good news, which we can see from David’s interaction with the giant, is that those who stand for God and God’s way, no matter what it seems they have as disability or disadvantage, when God is providing for them, they will overcome. We are called to be those who will overcome (1 John 4:4; 5:4-5), and this will happen when we rely on God for our strength, no matter how mighty the enemy seems. Those who, like the nephilim, rely on their own strength will not overcome.