Sons of God, Daughters of Men, and Giants
Some have taught that Genesis 6 describes fallen angels interbreeding with human women to produce half-demon giants. But there is a more rational explanation.
Halley’s Bible Handbook states that “the ‘sons of God’ (Genesis 6:2 Genesis 6:2That the sons of God saw the daughters of men that they were fair; and they took them wives of all which they chose.
American King James Version×) are thought to have been either fallen angels…or leaders in Sethite families who intermarried with the godless descendants of Cain” (24th ed., p. 72). The first possibility offered here is not really a possibility at all, even though angels are referred to as “sons of God” in Job 38:7 Job 38:7When the morning stars sang together, and all the sons of God shouted for joy?
American King James Version×because God is their “Father” through creation. Angels are spirit beings (Hebrews 1:7 Hebrews 1:7And of the angels he said, Who makes his angels spirits, and his ministers a flame of fire.
American King James Version×), not fleshly creatures. They neither marry nor sexually reproduce (compare Luke 20:34-36 Luke 20:34-36  And Jesus answering said to them, The children of this world marry, and are given in marriage:  But they which shall be accounted worthy to obtain that world, and the resurrection from the dead, neither marry, nor are given in marriage:  Neither can they die any more: for they are equal to the angels; and are the children of God, being the children of the resurrection.
American King James Version×). Also, this explanation would violate the principle made clear in Genesis 1 that each kind reproduces only “according to its kind.” Furthermore, the risen Jesus explained that “fallen angels,” or demons, are not able to manifest themselves materially like He and the righteous angels can (Luke 24:39 Luke 24:39Behold my hands and my feet, that it is I myself: handle me, and see; for a spirit has not flesh and bones, as you see me have.
American King James Version×; compare verses 40-43; Genesis 18:1-8 Genesis 18:1-8  And the LORD appeared to him in the plains of Mamre: and he sat in the tent door in the heat of the day;  And he lift up his eyes and looked, and, see, three men stood by him: and when he saw them, he ran to meet them from the tent door, and bowed himself toward the ground,  And said, My LORD, if now I have found favor in your sight, pass not away, I pray you, from your servant:  Let a little water, I pray you, be fetched, and wash your feet, and rest yourselves under the tree:  And I will fetch a morsel of bread, and comfort you your hearts; after that you shall pass on: for therefore are you come to your servant. And they said, So do, as you have said.  And Abraham hastened into the tent to Sarah, and said, Make ready quickly three measures of fine meal, knead it, and make cakes on the hearth.  And Abraham ran to the herd, and fetched a calf tender and good, and gave it to a young man; and he hurried to dress it.  And he took butter, and milk, and the calf which he had dressed, and set it before them; and he stood by them under the tree, and they did eat.
American King James Version×, Genesis 18:16 Genesis 18:16And the men rose up from there, and looked toward Sodom: and Abraham went with them to bring them on the way.
American King James Version×; Genesis 19:1 Genesis 19:1And there came two angels to Sodom at even; and Lot sat in the gate of Sodom: and Lot seeing them rose up to meet them; and he bowed himself with his face toward the ground;
American King James Version×). Rather, we see demons in Scripture only possessing individuals or appearing as ghostly apparitions.
The second explanation in Halley’s is far more reasonable and better fits the context of the passage. Genesis 4 gives the story of Cain and Abel and follows with the genealogical descent from Cain. Genesis 5 is called “the book of the genealogy of Adam” (verse 1). It starts with God’s creation of Adam and how Adam’s line continued through Seth. As with the angels, Adam was a “son of God” by creation (compare Luke 3:38 Luke 3:38Which was the son of Enos, which was the son of Seth, which was the son of Adam, which was the son of God.
American King James Version×)—though even more so since Adam was made in God’s image (Genesis 1:26 Genesis 1:26And God said, Let us make man in our image, after our likeness: and let them have dominion over the fish of the sea, and over the fowl of the air, and over the cattle, and over all the earth, and over every creeping thing that creeps on the earth.
American King James Version×; Genesis 5:1-3 Genesis 5:1-3  This is the book of the generations of Adam. In the day that God created man, in the likeness of God made he him;  Male and female created he them; and blessed them, and called their name Adam, in the day when they were created.  And Adam lived an hundred and thirty years, and begat a son in his own likeness, and after his image; and called his name Seth:
American King James Version×). Of this family line through Seth it is stated, “Then men began to call on the name of the Lord”—which could also be rendered “called after the name of the Lord.” Then, in the next chapter, Genesis 6, we see “the sons of God” (men of Seth’s godly line in this explanation) intermarrying with “the daughters of men” (women of Cain’s ungodly line).
There is even a third possibility, in which “sons of God” should be translated “sons of the gods,” as the Hebrew word elohim here, plural in form, can sometimes refer to false gods instead of the true God. In this explanation, wicked men referred to as sons of the gods (either pagan worshipers or perhaps men claiming to be demigods themselves) forcibly “took” innocent women as wives—an example perhaps of the evil conduct of the day.
In any event, human beings were clearly the problem here—not angels. God says, “My Spirit shall not strive with man forever” (verse 3) and “I will destroy man whom I have created from the face of the earth” (verse 7). Thus, the giants mentioned must have been human also—descendants of Adam and Eve (compare Acts 17:26 Acts 17:26And has made of one blood all nations of men for to dwell on all the face of the earth, and has determined the times before appointed, and the bounds of their habitation;
American King James Version×). These very tall people were destroyed in the Flood. But there would be more like them following the Flood, who were descended, just as everyone else in the post-Flood world, from Noah—again, not angels (compare Deuteronomy 2:20-21 Deuteronomy 2:20-21  (That also was accounted a land of giants: giants dwelled therein in old time; and the Ammonites call them Zamzummims;  A people great, and many, and tall, as the Anakims; but the LORD destroyed them before them; and they succeeded them, and dwelled in their stead:
American King James Version×; 3:11). Consider Goliath, whom David slew. He was more than nine feet tall (1 Samuel 17:4 1 Samuel 17:4And there went out a champion out of the camp of the Philistines, named Goliath, of Gath, whose height was six cubits and a span.
American King James Version×). But he was still just a man (verses 24-25, 33)—not some human-demonic hybrid.
The Antediluvian World
The antediluvian world should be a subject of interest to all Christians living in the end times, for Jesus explicitly connected end-time conditions with those just before the Flood (Matthew 24:38 Matthew 24:38For as in the days that were before the flood they were eating and drinking, marrying and giving in marriage, until the day that Noe entered into the ark,
American King James Version×).
Genesis 6 presents a picture of the pre-Flood world as being awash in violence, which was the natural consequence of the human heart being wholly motivated by evil purposes. As verse 5 says, “The Lord saw that the wickedness of man was great in the earth, and that every intent of the thoughts of his heart was only evil continually.” All of man’s motivating dispositions were dominated by evil. Man’s continual intention was the pursuit of ungodly purposes. “For as he thinks in his heart, so is he,” the Proverbs tell us (Proverbs 23:7 Proverbs 23:7For as he thinks in his heart, so is he: Eat and drink, said he to you; but his heart is not with you.
American King James Version×). And Jesus was equally clear: “Out of the heart proceed evil thoughts” (Matthew 15:19 Matthew 15:19For out of the heart proceed evil thoughts, murders, adulteries, fornications, thefts, false witness, blasphemies:
American King James Version×). Yet Jesus also tells us that despite the appalling evils and evident social degeneracy, the people of Noah’s time just continued with their normal daily living, “eating and drinking, marrying and giving in marriage,” seemingly oblivious to the miserable state of their world. But that is what sin does—it progressively desensitizes one to the ungodly conditions around him.
In many respects, our modern, frantic, pulsating 21st-century world is in or approaching the same condition as the ancient world of Noah. Stop and consider our societies. Violence and depravity are everywhere—and considered highly profitable and entertaining. For example our sports and popular entertainment are filled with strife, brutality, assault and murder. The news of the day chronicles endless crime. The streets of our cities are avenues of bloodshed and thievery. Sex and sensuality are not only ever-present but literally pushed in our faces as our cultural icons engage in and promote open eroticism and perverse “alternative” lifestyles, while semi-nude women are used to hawk everything from cars to health care. Unmarried couples living together is common, and about half of all American marriages are destined for divorce. Despite the “liberation” promised by the sexual revolution, violence against women and poverty for households headed by single women stand at an all-time high. Children are abused and exploited on a scale that is truly shocking. As conditions worsen, more and more of the signs that Jesus said would mark the last days are becoming apparent.