It’s easy, in reading through the first few chapters of Genesis, to miss a single verse—a verse that, when parsed and examined a little closer, should lead anyone to scratch their heads.
The Nephilim were on the earth in those days—and also afterward—when the sons of God went to the daughters of humans and had children by them. They were the heroes of old, men of renown (Gen. 6:4).
Wait, wait — so what happened? These “Nephilim,” who were apparently on the earth but are no longer so, came to earth, had sex with a bunch of earth women, which resulted in “the heroes of old,” and then departed. What. The. Hell?
First of all, you may ask, who were the “Nephilim”? If they sound like angels (“Seraphim” may ring a bell) it’s because they were. Well, probably. The Nephilim were angels, at least according to some early sources. (Others suggest they were offspring of Seth, the first human made in the image of adam, who, of course, was himself made in the image of God.*) Still others translate this word as more roughly “giants,” which correlates with the only other time the term appears in the Hebrew Bible (Num. 13:32-33). The Wikipedia page is actually pretty good, if you are interested in further reading and the multitude of interpretations.
But for Holey Books, let’s just consider the factual scenario here. To put it in other terms, Genesis makes a throwaway reference to a bunch of giants, giant angels, or demigod dudes who came out, took advantage of human women, and then, like bad fathers, jumped ship. This resulted in a bunch of evil and sin (that apparently humans had no control over?) and a rather more famous passage of Genesis:
The LORD saw how great the wickedness of the human race had become on the earth, and that every inclination of the thoughts of the human heart was only evil all the time. The LORD regretted that he had made human beings on the earth, and his heart was deeply troubled (Gen. 6:5-6).
Of course, what follows this verse is the account of the flood. After a bunch of God’s angels (or giants or whatever) came and seriously messed stuff up on Earth, God, like the benevolent ruler full of love we know him to be, apparently pulled a giant Ctrl-Z.
*Cain and Abel, however, were never noted in Genesis to be made “in the image” of God.