Answer
The Nephilim (“fallen ones, giants”) may have been the offspring of sexual relationships between the sons of God and the daughters of men in Genesis 6:1–4. There is much debate as to the identity of the Nephilim (verse 4) and the “sons of God” (verse 2), who seem to be distinct from the “human beings” in verse 1.
One theory is that the “sons of God” were fallen angels (demons) who took on physical form and mated with human females (or demons who possessed human males who then mated with human females). These unions resulted in extraordinary offspring, the Nephilim, who were “heroes of old, men of renown” of a giant size and, apparently, enhanced physical abilities (Genesis 6:4). If demons were involved in producing the Nephilim, it is likely those demons are the ones who were judged by God and are now “kept in darkness, bound with everlasting chains for judgment on the great Day” (Jude 1:6).
Assuming the Nephilim were the spawn of demons, why would demons want to cohabit with human women and produce offspring? One speculation is that the demons were attempting to pollute the human bloodline in order to prevent the coming of the Messiah. God had promised that the Messiah would one day crush the head of the serpent, Satan (Genesis 3:15). The demons in Genesis 6 were possibly attempting to prevent the crushing of the serpent and make it impossible for a sinless “seed of the woman” to be born.
There are at least two objections to the theory that the Nephilim were demon-human hybrids: first, there is nothing in the text to expressly identify the sons of God as angels. Second, the Bible never indicates that angels are physiologically compatible with women and can procreate with them (unless Genesis 6 is the only instance).
Others have suggested that the sons of God might be fallen angels who possessed men. As in the first theory, the phrase sons of God could still refer to fallen angels, the difference being that the demons were using mortal men to accomplish their goals. While this view would resolve the physiological problems of the first theory, there is, again, nothing in the text to suggest demonic possession.
Another view of the Nephilim is that the statement “There were giants on the earth in those days” (Genesis 6:4, NKJV) simply means that everyone was big and tall and mighty. Genetically, humanity was still in a nearly pristine condition. This theory takes the view that these sons of God were simply men. This would explain why there were giants before the flood “and also afterward” (Genesis 6:4; cf. 1 Samuel 17:4–7), as primeval genetic material survived in Noah’s family. The fact that Nephilim were still around sporadically after the flood is an indicator that giants like Goliath were exceptional, but not superhuman.
According to legend (the Book of Enoch and other non-biblical writings), the Nephilim were a unique race of giants and superheroes who committed acts of great evil. In the 2014 movie Noah, starring Russell Crowe, the Nephilim are fallen angels encased in rock. All that the Bible directly says about the Nephilim is that they were “heroes and famous warriors of ancient times” (NLT) or “powerful men of old, the famous men” (CSB). The Nephilim were not aliens, angels, “Watchers,” or rock monsters; they were literal, physical beings.
As mentioned, there were some Nephilim after the flood, according to Genesis 6:4. When the Israelites spied out the land of Canaan, they reported back to Moses, “We saw the Nephilim there (the descendants of Anak come from the Nephilim). We seemed like grasshoppers in our own eyes, and we looked the same to them” (Numbers 13:33). Later, as Moses addressed the people of Israel before they entered Canaan, he mentioned the sons of Anak: “You are now about to cross the Jordan to go in and dispossess nations greater and stronger than you, with large cities that have walls up to the sky. The people are strong and tall—Anakites! You know about them and have heard it said: ‘Who can stand up against the Anakites?’” (Deuteronomy 9:1–2). These “giants” were destroyed by the Israelites with God’s help (Deuteronomy 3:10–11; 9:3; Joshua 11:21–22; 1 Samuel 17).
It’s a mysterious passage, but Genesis 6:4 states that there were Nephilim in the land in the days before the flood. The passage does not explicitly say how these giants came to be. It is best to not be dogmatic on an issue that the Bible says so little about and that is not theologically significant in the grand scheme of things.
