Scriptures:
Genesis 6:1, 2. – Now it came to pass, when men began to multiply on the face of the earth, and daughters were born to them, that the sons of God saw the daughters of men, that they were beautiful; and they took wives for themselves of all whom they chose.
Genesis 6:4. – There were giants on the earth in those days, and also afterward, when the sons of God came in to the daughters of men and they bore children to them. Those were the mighty men who were of old, men of renown.
Job 1:6 – Now there was a day when the sons of God came to present themselves before the Lord, and Satan also came among them.
Job 38:6–7 – On what were its bases sunk, or who laid its cornerstone, when the morning stars sang together and all the sons of God shouted for joy?
2 Peter 2:4, 5. – God did not spare the angels who sinned, but cast them down to hell and delivered them into chains of darkness, to be reserved for judgment; and did not spare the ancient world, but saved Noah.
Jude 1:6 – The angels who did not keep their proper domain, but left their own habitation, he has reserved in everlasting chains under darkness for the judgment of the great day.
1 Enoch 7:1-2 – It happened after the sons of men had multiplied in those days, that daughters were born to them, elegant and beautiful. And when the angels, the sons of heaven, beheld them, they became enamoured of them, saying to each other, “Come, let us select for ourselves wives from the progeny of men, and let us beget children.”
Enoch 7:10-15 – Then they took wives, each choosing for himself; whom they began to approach, and with whom they cohabited; teaching them sorcery, incantations, and the dividing of roots and trees. And the women conceiving brought forth giants, whose stature was each three hundred cubits. These devoured all which the labor of men produced; until it became impossible to feed them; when they turned themselves against men, in order to devour them; and began to injure birds, beasts, reptiles, and fishes, to eat their flesh one after another, (8) and to drink their blood. Then the earth reproved the unrighteous.
Enoch 10:6-9 – Again the Lord said to Raphael, Bind Azazyel hand and foot; cast him into darkness; and opening the desert which is in Dudael, cast him in there. Throw upon him hurled and pointed stones, covering him with darkness; there shall he remain for ever; cover his face, that he may not see the light. And in the great day of judgment let him be cast into the fire.
Church Fathers
All things therefore being completed which are in heaven, and in earth, and in the waters, and the human race also having multiplied, in the eighth generation, righteous men, who had lived the life of angels, being allured by the beauty of women, fell into promiscuous and illicit connections with these; and thenceforth acting in all things without discretion, and disorderly, they changed the state of human affairs and the divinely prescribed order of life, so that either by persuasion or force they compelled all men to sin against God their Creator. In the ninth generation are born the giants, so called from of old, not dragon-footed, as the fables of the Greeks relate, but men of immense bodies, whose bones, of enormous size, are still shown in some places for confirmation. But against these the righteous providence of God brought a flood upon the world, that the earth might be purified from their pollution, and every place might be turned into a sea by the destruction of the wicked. – Recognitions of Clement, Book 1, Chapter 29
“But when, having assumed these forms, they convicted as covetous those who stole them, and changed themselves into the nature of men, in order that, living holily, and showing the possibility of so living, they might subject the ungrateful to punishment, yet having become in all respects men, they also partook of human lust, and being brought under its subjection they fell into cohabitation with women; and being involved with them, and sunk into defilement and altogether emptied of their power, were unable to turn back to the first purity of their proper nature, their members turned away from their fiery substance: for the fire itself, being exhausted by the weight of lust, and changed into flesh, they trode the impious path downward. For they themselves, being fettered with bonds of flesh, were constrained and strongly bound; wherefore they have no more been able to ascend into the heavens.” – Clementine Homilies, Homily VIII, Chapter XIII.
The angels transgressed this appointment and were captivated by love of women. And they begat children, who are those who are called demons. – Justin Martyr (c. 160, E), 1.190.
Angels sinned and revolted from God. – Justin Martyr (c. 160, E), 1.238.
The other angels were created by Him, and entrusted with the control of matter and the forms of matter. . . . Just as with men, they have freedom of choice as to both virtue and vice. . . . Some men are diligent in the matters entrusted to them by you, and others are faithless. It is the same among the angels. They are free agents, being created that way by God, as you will observe. Some of them have continued in those things for which God had made them. They have remained over the things to which He had ordained them. But some outraged both the constitution of their nature and the oversight entrusted to them. . . . These angels fell into impure love of virgins and were subjugated by the flesh. . . . Those who are called giants were begotten from these lovers of virgins. – Athenagoras (c. 175, E), 2.142.
These angels, then, who have fallen from heaven, and haunt the air and the earth, and are no longer able to rise to heavenly things, and the souls of the giants, who are the demons who wander about the world, perform similar actions. – Athenagoras (c. 175, E), 2.142.
“And for a very long while wickedness extended and spread, and reached and laid hold upon the whole race of mankind, until a very small seed of righteousness remained among them and illicit unions took place upon the earth, since angels were united with the daughters of the race of mankind; and they bore to them sons who for their exceeding greatness were called giants.” – Irenaeus, Demonstration of Apostolic Preaching, Chapter 18
Since the Son of God is always one and the same, He gives to those who believe on Him a well of water [springing up] to eternal life, but He causes the unfruitful fig-tree immediately to dry up; and in the days of Noah He justly brought on the deluge for the purpose of extinguishing that most infamous race of men then existent, who could not bring forth fruit to God, since the angels that sinned had commingled with them, and [acted as He did] in order that He might put a check upon the sins of these men, but [that at the same time] He might preserve the archetype, the formation of Adam. – Irenæus, Against Heresies Book IV, Chapter XXXVI
The angels who had obtained the superior rank, having sunk into pleasures, told the women the secrets that had come to their knowledge. In contrast, the rest of the angels concealed them, or rather, reserved them for the coming of the Lord. – Clement of Alexandria (c. 195, E), 2.446.
It will therefore be manifest to you, that the goodness of God is great toward man, and that freedom has been given to him in greater measure than to any of those elemental bodies of which we have spoken, in order that by this freedom he may justify himself, and order his conduct in a godlike manner, and be copartner with angels, who are likewise possessed of personal freedom. For we are sure that, if the angels likewise had not been possessed of personal freedom, they would not have consorted with the daughters of men, and sinned, and fallen from their places. In like manner, too, those other angels, who did the will of their Lord, were, by reason of their self-control, raised to higher rank, and sanctified, and received noble gifts. For every being in existence is in need of the Lord of all; of His gifts also there is no end. – Bardesanes, The Book of the Laws of Various Countries, chapter 1
By our sacred books, we are instructed how from certain angels, who fell of their own free will, there sprang an even more wicked demon brood. – Tertullian (c. 197, W), 3.36.
Those angels who invented them [jewelry, etc.] are assigned under condemnation to the penalty of death. They are the same angels who rushed from heaven on the daughters of men. . . . If it is true, they laid bare the operations of metallurgy, divulged the natural properties of herbs, promulgated the powers of enchantments, and traced out every curiosity, even to the interpretation of the stars. They conferred appropriately—and as it were, peculiarly—upon women that instrumental means of womanly ostentation: the radiances of jewels, . . . the dyes of orchil with which wools are dyed, and that black powder itself with which the eyelids and eyelashes are made prominent. – Tertullian (c. 198, W), 4.14, 15.
I lay down this one proposition: that those angels—the deserters from God, the lovers of women—were likewise the discoverers of this curious art [of astrology]. And on that account, they were also condemned by God. . . . For we know the mutual alliance of magic and astrology. – Tertullian (c. 200, W), 3.65.
For indeed it is “on account of the angels” that he said women must be veiled, because on account of “the daughters of men” angels revolted from God. – Tertullian, On Prayer, chapter 22
Apostate and refugee powers that have departed from God—because of the very wickedness of their mind and will, or from envy … invented many errors and delusions of false doctrine in order to prevent any progress. – Origen (c. 225), 4.336.
It is true of all demons that they were not originally demons. Rather, they became so in departing from the true way. Accordingly, the name “demon” is given to those beings who have fallen away from God. – Origen (c. 248), 4.638.
Such was the beauty of women that it turned the angels aside. As a result, being contaminated, they could not return to heaven. Being rebels from God, they uttered words against Him. Then the Highest uttered His judgment against them. And from their seed, giants are said to have been born. By them, arts were made known in the earth. They taught the dyeing of wool and everything that is done. When they died, men erected images to them. – Commodianus (c. 240, W), 4.203.
From the seed [of the fallen angels and women], giants are said to have been born. By them, arts were made known in the earth. They taught the dyeing of wool and everything that is done. When they died, men erected images to them. Yet, because they were of an evil seed, the Almighty did not approve of their being brought back from death when they had died. For that reason, they wander and they now subvert many bodies. And it is these whom you [pagans] presently worship and pray to as gods. – Commodianus (c. 240, W), 4.203.
When men multiplied on the earth, the angels of heaven came together with the daughters of men. In some copies, I found “the sons of God.” What the Spirit means, in my opinion, is that the descendants of Seth are called the sons of God, because of the righteous men and patriarchs who have sprung from him (even down to the Savior himself). However, the descendants of Cain are named the seed of men, as having nothing divine in them, because of the wickedness of their race. . . . However, if it is thought that these refer to angels, we must take them to be those who deal with magic and sorcery, who taught the women the motions of the stars and the knowledge of things celestial. By the power of those angels, they conceived the giants as their children, by whom wickedness reached its peak on the earth. Finally, God decreed that the whole race of the living should perish in their impiety by the deluge. – Julius Africanus (c. 245, E), 6.131.
All of these things [i.e., the making of jewelry] the sinning and apostate angels put forth by their arts, when, lowered to the contagions of earth, they forsook their heavenly vigor. They also taught women to paint the eyes with blackness drawn around them in a circle and to stain the cheeks with a deceitful red. – Cyprian (c. 250, W), 5.434.
God, in His foresight, sent angels for the protection and improvement of the human race—lest the devil . . . should either corrupt or destroy men through his subtlety. Since He had given these angels a free will, He admonished them above all things not to defile themselves with contamination from the earth and thus lose the dignity of their heavenly nature. . . . However, while the angels lived among men, that most deceitful ruler of the earth, by his very association, gradually enticed them to vices and polluted them through sexual relations with women. Thereafter, not being admitted into heaven because of the sins into which they had plunged themselves, they fell to the earth. – Lactantius (c. 304–313, W), 7.64.
They strive to turn men away from the worship and knowledge of the true Majesty, so men will not be able to obtain immortality. That is because these angels lost [immortality] because of their wickedness. – Lactantius (c. 304–313, W), 7.66.
Although they are the destroyers of men, they wish to appear as men’s guardians—so that they themselves will be worshipped and so that God will not be worshipped. – Lactantius (c. 304-313), 7.64.
However, those who were born from [the relations of angels with women]—because they were neither angels nor men, but had a mixed nature—were not admitted into Hades [when they died]. Similarly, their fathers had not been admitted into heaven, either. Thus there came to be two kinds of demons: one of heaven, the other of the earth. The latter are the wicked spirits, who are the authors of all the evils that are done. This same devil is their prince. . .. However, grammarians say that the reason they are called demons . . . is because they are skilled and acquainted with matters. For the grammarians think they are gods. In truth, the demons are acquainted with some future events, but not with all. For He has not permitted them to know entirely the counsel of God . . . . – Lactantius (c. 304-313), 7.64; extended discussion: 4.328-4.334
Certain of the angels, refusing to submit themselves to the commandment of God, resisted His will. And one of them indeed fell like a flash of lightning upon the earth, while others, harassed by the dragon, sought pleasure in sexual relations with the daughters of men, and thus brought on themselves the deserved recompense of the punishment of eternal fire. – Disputation of Archelaus and Manes (c. 320, E), 6.205.
Thus, Er, the first son, represents the original people—the demigods, the mightiest men and kings—who, in their wild strength and unchecked desires, waged war and devastated the entire earth. They even claimed temples instead of houses for themselves, erected altars in their own names, and yet did not know what kind of grave they would one day find. They promised themselves heaven, though their actions would have made the earth blush with shame if that had been possible. In the end, they even declared themselves gods before God, though people of sound mind would not have deemed them worthy of being called men. For these reasons, they were not only destroyed by God but also condemned to eternal judgment. – Zeno of Verona, Book 2, Treatise 14, Chapter 2
The giants (Nephilim) were on the Earth in those days.” The author of the divine Scripture does not mean that those giants must be considered, according to the tradition of poets, as sons of the earth but asserts that those whom he defines with such a name because of the extraordinary size of their body were generated by angels and women. — Ambrose, on Noah, 4.8. Genesis 1–11
Other References:
Jubilees 5:1-2 – And it came to pass when the children of men began to multiply on the face of the earth and daughters were born unto them, that the angels of God saw them on a certain year of this jubilee, that they were beautiful to look upon; and they took themselves wives of all whom they chose, and they bare unto them sons and they were giants. And lawlessness increased on the earth and all flesh corrupted its way, alike men and cattle and beasts and birds and everything that walks on the earth – all of them corrupted their ways and their orders, and they began to devour each other, and lawlessness increased on the earth and every imagination of the thoughts of all men (was) thus evil continually.
Testament of Reuben, chapter 5: Hurtful are women, my children; because, since they have no power or strength over the man, they act subtly through outward guise how they may draw him to themselves; and whom they cannot overcome by strength, him they overcome by craft. For moreover the angel of God told me concerning them, and taught me that women are overcome by the spirit of fornication more than men, and they devise in their heart against men; and by means of their adornment they deceive first their minds, and instill the poison by the glance of their eye, and then they take them captive by their doings, for a woman cannot overcome a man by force.
Therefore flee fornication, my children, and command your wives and your daughters that they adorn not their heads and their faces; because every woman who acts deceitfully in these things has been reserved to everlasting punishment. For thus they allured the Watchers before the flood; and as these continually beheld them, they fell into desire each of the other, and they conceived the act in their mind, and changed themselves into the shape of men, and appeared to them in their congress with their husbands; and the women, having in their minds desire toward their apparitions, gave birth to giants, for the Watchers appeared to them as reaching even unto heaven.
On what principle it was that giants were born of angels and women? (Genesis 6:4): But he [Moses] relates that these giants were sprung from a combined procreation of two natures, namely, from angels and mortal women; for the substance of angels is spiritual; but it occurs every now and then that on emergencies occurring they have imitated the appearance of men, and transformed themselves so as to assume the human shape; as they did on this occasion, when forming connections with women for the production of giants. But if the children turn out imitators of the wickedness of their mothers, departing from the virtue of their fathers, let them depart, according to the determination of the will of a depraved race, and because of their proud contempt for the supreme Deity, and so be condemned as guilty of voluntary and deliberate wickedness. But sometimes Moses styles the angels the sons of God, inasmuch as they were not produced by any mortal, but are incorporeal, as being spirits destitute of any body. – Philo of Alexandria, Questions, question 92
“And when the angels of God saw the daughters of men that they were beautiful, they took unto themselves wives of all of them whom they Chose.” (Genesis 6:2.} Those beings, whom other philosophers call demons, Moses usually calls angels; and they are souls hovering in the air. And let no one suppose, that what is here stated is a fable, for it is necessarily true that the universe must be filled with living things in all its parts, since every one of its primary and elementary portions contains its appropriate animals and such as are consistent with its nature; –the earth containing terrestrial animals, the sea and the rivers containing aquatic animals, and the fire such as are born in the fire (but it is said, that such as these last are found chiefly in Macedonia), and the heaven containing the stars. – Philo of Alexandra, On The Giants, chapter 2
For many angels of God coupled with women, and begat sons that proved unjust and despisers of all that was good, on account of the confidence they had in their own strength; for the tradition is, that these men did what resembled the acts of those whom the Grecians call giants. – Josephus, Antiquities of the Jews 1.73
Jubilees 4:22 – And he testified to the Watchers, who had sinned with the daughters of men; for these had begun to unite themselves, so as to be defiled, with the daughters of men, and Enoch testified against (them) all.
And it came to pass when the sons of men began to multiply on the face of the ground, and beautiful daughters were born to them, that the sons of the great ones saw that the daughters of men were beautiful, with eyes painted and hair curled, walking with uncovered flesh, and they conceived lustful thoughts; and they took them wives of all they chose. . . . Shamhazai and Azael fell from heaven and were on earth in those days, and also after that, when the sons of the great ones came in unto the daughters of men, and they bare children to them: the same are called men of the world, the men of renown. – Targum Pseudo-Jonathan 6:1–4
2 Baruch 56:10-15 – For he became a danger to his own soul: even to the angels For, moreover, at that time when he was created, they enjoyed liberty. And became he a danger some of them descended, and mingled with the women. And then those who did so were tormented in chains. But the rest of the multitude of the angels, of which there is (no) number, restrained themselves. And those who dwelt on the earth perished together (with them) through the waters of the deluge.
The Big Reversal:
From Adam Seth was born, who was the third after Abel, and from Seth Enosh was born. He hoped to be called the Lord and God. Therefore the children born from him bear the name ‘sons of God’, just like we also from the name of the master Christ are called Christians. The race of Seth was segregated and not mixed with the race of Cain because of the curse which was laid on him by the God of the universe. But later, when they observed how beautiful the daughters of Cain’s family were, they became enchanted and took them for themselves as wives, thus ruining their ancestral nobility. – Athanasius of Alexandria, Interpretationes ex Veto Testamento, Quaestio 65
We made the point before in teaching you that it is customary with Scripture to call human beings sons of God. So, since these people took their origin from Seth and from his son named Enosh those descended from him in future were called sons of God by Sacred Scripture for the reason of their imitation of the virtue of their ancestors up to his time. On the other hand, he gave the name sons of men to those born after Seth, the descendants of Cain and those taking their descent from him. – John Chrysostom, Homilies on Genesis, Homily 22
When the human race, in the exercise of this freedom of will, increased and advanced, there arose a mixture and confusion of the two cities by their participation in a common iniquity. And this calamity, as well as the first, was occasioned by woman, though not in the same way; for these women were not themselves betrayed, neither did they persuade the men to sin, but having belonged to the earthly city and society of the earthly, they had been of corrupt manners from the first, and were loved for their bodily beauty by the sons of God, or the citizens of the other city which sojourns in this world. – Augustine, City of God, chapter 22
That we rightly understand this passage is also very much confirmed by the interpretation of the other translators. Aquila says: ‘When the sons of the gods saw the daughters of men’. On the other hand, instead of ‘sons of the gods’, Symmachus rendered the expression as ‘sons of the rulers’. They called the descendants of Seth and of Enosh sons of the gods, or better, sons of the rulers, because of the piety and godliness which was in them, and because they could defeat all adversaries: while God, I suppose, in all likelihood came to their aid, and made known all around this pious and holy generation, which was not mixed with that other one, that is to say, with the descendants from Cain and, what is more, from Lamech. – Cyril of Alexandria, Glaphyra in Genesim 2.1