On the Nephilim
Genesis 6:1-8 (RVIC). “And it came to pass, when man began to multiply on the face of the ground, and daughters were born unto them, (2) that the sons of God saw the daughters of man that they were fair; and they took them wives of all that they chose. (3) And Jehovah said, My Spirit shall not strive in man for ever, in their going astray they are flesh: his days shall be yet a hundred twenty years. (4) The Nephilim were in the earth in those days, and also after that, when the sons of God came in unto the daughters of man, and they bare children to them: the same were the mighty men that were of old, the men of renown. (5) And Jehovah saw that the wickedness of man was great in the earth, and that every imagination of the thoughts of his heart was only evil continually. (6) And it repenteth Jehovah that he had made man on the earth, and it grieved him at his heart. (7) And Jehovah said, I will destroy man whom I have created from the face of the ground; both man, and beast, and creeping things, and birds of the heavens; for it repented me that I have made them. (8) But Noah found favor in the eyes of Jehovah.”

The flood removed the Nephilim.
Fallen angels materialized and mated with human women to produce human sons (verses 2-3). The claim that the Nephilim survived the Flood, and were a threat to Israel, was a lie (Numbers 13:25-33). At first, the ten lying spies said only that the sons of Anak were in the land (Numbers 13:28). But when Caleb told the Israelites that they were well able to overcome the land, the ten lying spies panicked and even claimed they had seen Nephilim — a gross exaggeration to defend their position. Nowhere else is there assertion that the Nephilim continued after the Flood.
The sons of (fallen) angels inherited their nature from their mothers (human) and their rights from their fathers (angels). Thus, they were not under the Adamic penalty; so it would be necessary to kill them, rather than wait for them to somehow die naturally. Hence, the Flood.
Yehovah repented, in that he changed his ways of dealing with humans (both kinds), by sending the Flood at the time of His choosing. There is no suggestion that God had sinned (man had), only that he was changing His course of action.
Technical point, in verse 4, the Nephilim apparently precede the progeny of the sons of God (angels) — “and also after that.” The word “naphal” means “to fall.” Thus, “Nephilim” is a plural noun and so means “the fallen ones.” So there may be two groups mentioned in this verse, the fallen ones of Adamic descent, and later the progeny of the fallen angels also.
In any case, Yehovah God gave them an extra 120 years before destroying them in the Flood.
Giants after the Flood are called Rephayim (20 times, including Genesis 14:5, 15:20, Deuteronomy 2:11). Among them were the Ghanaqim/Anakim (“long-necked’) in and around Hebron, in the south of Israel, and apparently eliminated by Joshua. Another was Goliath, who was about 9 feet 6 inches tall (1 Samuel 17:4). (For comparison, Robert Pershing Wadlow, 1918-1940, of Alton, Illinois, was 8 feet 11 inches tall. He was healthy, and still growing, when a septic blister caused his death at age 22.) Og, king of Bashan, may have been still taller (Deuteronomy 2:11).
— Br. Jim Parkinson
