Most Bible scholars trace the word "Nephilim" (NEF-ill-im) to the Hebrew root "Naphal" meaning "to fall." Nephilim can also mean ‘rejects’. Some Angels were apprentices of Satan, and, with him, they rebelled against God. They were “angels who did not stay within the limits of authority God gave them.” (Jude 1:6). They mated with human women and produced a perverted hybrid race - "When men began to increase in number on the earth and daughters were born to them, The sons of God saw that the daughters of men were beautiful, and they married any of them they chose. (‘Sons of God’ in the Old Testament always refers to angels). The Nephilim were on the earth in those days …when the sons of God went to the daughters of men and had children by them. They were the heroes of old, men of renown.” (Genesis 6:4) Hebrew scholars disagree as to whether the ‘mighty men of old’ were the Nephilim themselves or their demonic offspring. But, either way, the Bible confirms the sinful existence of these half-breeds. It is believed by many that these Nephilim or their hybrid offspring (‘ heroes of old, men of renown’) were the catalysts for such legendary figures as Atlas, Zeus, Hercules, Poseidon, and other mythological ‘heroes of old’ including those in Hindu, Inca, Sumer, and Egyptian mythologies.
The Genesis 6 verse above also says “Then the LORD said, "My Spirit will not contend with man forever…” The bloodlines of men on earth had become corrupted by this forbidden mating of the Nephilim with humans. However, we also read in Genesis 6 “Noah was a righteous man, blameless among the people of his time, and he walked faithfully with God (some scholars think him blameless because Noah’s blood was purely human and not tainted by the ungodly mixing of Nephal and human).
“ 11 Now the earth was corrupt in God’s sight and was full of violence. 12 God saw how corrupt the earth had become 13 So God said to Noah, “I am going to put an end to all people,” (Genesis 6:11) The worldwide flood enabled God to cleanse the earth of their wickedness and wipe out the unnatural offspring of the Nephilim. From the beginning, God intended for the Messiah to come through a pure line (of Abraham, Isaac and Jacob). This corrupted blood line of Nephilim could have tainted that Messianic line. Even from Eden, Satan has tried to pervert everything good that God has planned for mankind, including corrupting the blessed lineage of Jesus the Messiah (Messiah Yeshua). Every time Satan moves a chess piece on the board, God moves His piece too. It is destined that God will win the match. As current events testify, we are getting closer to ‘checkmate’. Shalom.