Some Bible scholars believe that these sons of God are fallen angels, who got married with daughters of men and bear children, that was wrong.
Genesis 6:1-4 (KJV)
And it came to pass when men began to multiply on the face of the earth, and daughters were born unto them,
2 That the sons of God saw the daughters of men that they were fair; and they took them wives of all which they chose.
3 And the Lord said, My spirit shall not always strive with man, for that he also is flesh: yet his days shall be a hundred and twenty years.
4 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.
Note verse 3: And the Lord said My spirit shall not always strive with man, the bible didn’t say my spirit will not always strive with angels.
Genesis 4:16-17 (KJV) And Cain went out from the presence of the Lord, and dwelt in the land of Nod, on the east of Eden.
17 And Cain knew his wife, and she conceived, and bare Enoch: and he built a city, and called the name of the city, after the name of his son, Enoch.
Cain was the son of Satan; the bible says so.
Genesis 3:15 (KJV)
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.
1 John 3:12 (KJV)
Not as Cain, who was of that wicked one, and slew his brother. And wherefore slew he him? Because his own works were evil, and his brother’s righteous.
Satan is a fallen angel, so Cain was the son of a fallen angel, Satan being his Pappa.
Cain went in the land of Nod with his wife, note: there was nobody there, why? because Adam and Eve were the first creatures God ever created. Cain married his own sister
because it was allowed in the old times. Women are not normally recorded when given birth.
In the land of Nod Cain and his wife started to multiply, Cain was giant, so his Pappa the devil, that was the mark God put on him so that no one will kill him.
The son’s of God are Seth lineage taking wives from Cain lineage, Genesis 6:3, My spirit shall not always strive with man, and his days shall be an hundred and twenty years.
In the land of Nod, Cain multiplies, which were fallen son’s of God, who came through his daddy the devil, and Satan being Cain’s daddy is a fallen angel.
Daughters of men, women are by product of a man, there was not among the initial creation, they were created through man, God created Eve through Adam, the better way to
address them women or daughters born to sons of God is to call them daughters of men.