I am using KJV.
Let's get back to reading the plain text. After the serpent beguiled the woman in Genesis 3:13, verses 14-15 then reveal:
And the LORD God said unto the serpent, Because thou hast done this, thou art cursed above all cattle, and above every beast of the field; upon thy belly shalt thou go, and dust shalt thou eat all the days of thy life: And I will put enmity between thee and the woman, and between thy seed and her seed; it shall bruise thy head, and thou shalt bruise his heel.
Therefore, these two very important questions need to be answered:
1. What or who is the seed of the woman?
2. What or who is the seed of the serpent?
After Eve bare Cain and Abel, Cain slew Abel and he was “cursed from the earth” (Gen. 4:1-12). This meant that the earth would not bring forth her strength to Cain. Cain’s “fruit of the ground” offering was unacceptable by the LORD. There had been no associated “shedding of blood” with that offering (See: Hebrews 9:22). On the other hand, blood was shed with Abel’s offering of the firstlings of his flock. Cain and Abel both knew full well that the LORD had required the shedding of blood when He clothed their father and mother with coats of skins after they had sinned. Cain continued to have grandchildren for Eve, but Cain was never appointed to pass the seed of the woman—neither before, nor after he slew Abel—according to Genesis 4:25:
And Adam knew his wife again; and she bare a son, and called his name Seth: For God, said she, hath appointed me another seed instead of Abel, whom Cain slew. (My emphasis)
All of Adam’s children, including both Cain and Seth, were born as Adam’s offspring—each in Adam’s likeness; after Adam’s image—alive in the flesh, but dead in the spirit. Each and every son or daughter, if he or she had so chosen, still had the ability to hear God’s Word and to believe that Word. Cain’s simply being the offspring of Adam and Eve was never reason to believe that he could pass on the seed of the woman. Cain was never actually appointed, so he could never pass on that seed. Only duly-appointed Seth could pass the seed of the woman.
Luke shows the genealogy of Jesus Christ, the Son of man--the seed of the woman. Luke 3:38, after going backwards from Jesus to Adam--son to father--only one son (seed) of each father, we finally see:
Which was the son of Enos, which was the son of Seth, which was the son of Adam, which was the son of God. (My emphasis)
So Adam was the first son of God. There are many reasons for this, but clearly, this was not accomplished through childbirth.
Hebrew people showed genealogies flowing from the father to the son, not from the mother to the son. The Notice of the special generations of the seed of the woman begins with Genesis 5:1 saying,
“This is the book of the generations of Adam”.
Genesis chapter 5 continues to track that seed of the woman by the generations of Adam—not Eve—to Noah through Seth—not Cain—one son per generation—one son for each father—one generation after its former.
And Adam lived an hundred and thirty years, and begat a son in his own likeness, after his image; and called his name Seth: (My emphasis) …
Following Seth, not every begotten son of Seth was named in this special generational lineage. Only Enos was designated as we see beginning at verse 3. All of Seth’s other sons and daughters were casually referred to in Genesis 5: 6-8, but only Enos was specifically named:
… And Seth lived an hundred and five years, and begat Enos: And Seth lived after he begat Enos eight hundred and seven years, and begat sons and daughters: And all the days of Seth were nine hundred and twelve years: and he died.
Genesis 6:4 is a recap of those days—beginning when Adam’s son Seth begat his own son, Enos—beginning when the sons of God came in unto the daughters of men, and they begat children to them:
There were giants in the earth in those days; and also after that, when the sons of God came in unto the daughters of men, and they bare children to them, the same became mighty men which were of old, men of renown. (My emphasis)
Some liberal theologians pervert this verse by claiming that “angels” procreated with daughters of men resulting in evil giants. In Matthew 22:29-30, Jesus clarified concerning the angels:
Jesus answered and said unto them, Ye do err, not knowing the scriptures, nor the power of God. For in the resurrection they neither marry, nor are given in marriage, but are as the angels of God in heaven. (My emphasis)
Fallen angels on earth did not have any more power to father children of men than did God’s angels in heaven. Angels are spirits. Only God and man had the power to father a child.
Notice also that first, there were the giants. Only “after that”—after the giants already existed,—when believing Seth began to pass the seed of the woman down through the daughters of men, did those men and their sons become “mighty men which were of old, men of renown.” Clearly, this was speaking about those believing sons of God on earth, beginning with Seth. Some giant water creatures were made by the Word of God on the fifth day. He also made earthly giants such as the behemoth on the sixth day—the same day that He made man according to Job 40:15:
Behold now behemoth, which I made with thee; he eateth grass as an ox. Lo now, his strength is in his loins, and his force is in the navel of his belly. He moveth his tail like a cedar: the sinews of his stones are wrapped together. His bones are as strong pieces of brass; his bones are like bars of iron. He is the chief of the ways of God: he that made him can make his sword to approach unto him. (My emphasis)
THE SONS OF GOD--THE LINEAGE OF THE SEED OF THE WOMAN.
These special “sons of God” from Seth through Noah to Joseph, the husband of Mary, clearly believed God because they recorded this lineage and passed along God’s message to their children as to mankind’s hope lying in the promised seed of the woman. These believing sons of God distinguished themselves by their belief from all those unbelievers whose names we will never know. Believers are those that are named that we read about and whose faith is recorded in and preserved by the Word of God. They who believed God’s spoken “promise” of the coming Savior were those who lived to become mighty men of old, men of renown. (Read: Heb. 11:1-40 for a list of some of those men of renown). So Seth is the beginning son of the line of the seed of the woman. Genesis 5 continues this lineage from Seth to Enos, and onward, on and on all the way to Noah. That line then continues from Noah through Shem all the way to Abram. Once again as others before, only one of Noah’s three sons, Shem—not Ham and not Japeth—passed along the seed of the woman. Chapter 10 of Genesis shows how the entire earth was populated by Noah and his three sons, but Chapter 11, verses 10-30 records only the believing line of the seed of the woman to Abram:
These are the generations of Shem: Shem was an hundred years old, and begat Arphaxad two years after the flood: . . . . Now these are the generations of Terah: Terah begat Abram, Nahor, and Haran; and Haran begat Lot. And Haran died before his father Terah in the land of his nativity, in Ur of the Chaldees. And Abram and Nahor took them wives: the name of Abram's wife was Sarai; and the name of Nahor's wife, Milcah, the daughter of Haran, the father of Milcah, and the father of Iscah. But Sarai was barren; she had no child.
Genesis 6:4 is speaking of "men of renown." The Hebrew word from which "renown" is transliterated from is (H8034) "shem".
The Heb, ***nephîyl*, means excellent, noble, skilful**. That is what the writer of Hebrews understood, plain and simple
THE SEED OF EVIL DOERS SHALL NEVER BE RENOWNED.
Lucifer was a man (Isaiah 14:16)--a certain king of Babylon (Isaiah 14:4-11) who is now dead physically but will be resurrected (Isaiah 14:19). He and the false prophet will be cast alive as resurrected men into the lake of fire a full thousand years before the other unbelievers are resurrected. Lucifer will not join those others who remain in burial for that full thousand years. Verse 20 plainly and clearly details:
Thou shalt not be joined with them in burial, because thou hast destroyed thy land, and slain thy people: the seed of evildoers shall never be renowned.
So the idea that angels could possibly father children through the daughters of men is totally speculative and unproven.
This answer uses quotes from pages 8-11 of God's Day-Five Creation, Life by grace through faith in the WORD of God.