Could the stories of Greek gods originate in the Nephilim of Genesis 6?
In Genesis 6, the Bible seems to suggest that the mythology of ancient cultures, including Greek and Roman mythology, may have found its source in the historical accounts of misbehaving demons. In the days prior to the flood, demons (fallen angels) committed gross sin by mating with earthly women to produce an unnatural, powerful offspring called Nephilim:
The offspring of the demons (i.e., the "sons of God") and earthly women were Nephilim. They were mighty men of ancient times and were renown, meaning their strength and accomplishments were legendary. Nevertheless, these “creatures” polluted the line of humanity, threatening God's plan to produce a Messiah in the seed of men, so God brought the flood to the earth to destroy all flesh including the Nephilim. Meanwhile, the legends of this strange and powerful human-like creatures lived on in the mythology of ancient man.