Who are the Sons of God that married the daughters of men?
That the sons of God saw that the daughters of men were beautiful; and they took wives for themselves, whomever they chose (Genesis 6:2).
They are not fallen Angels as some believe, they are those who have faith in God. I believe the term: “Daughters of men” refers to those of the fallen line from Adam. Jesus made this type of distinction when He spoke on two different occasions to women (“And this woman, a daughter of Abraham as she is, whom Satan has bound for eighteen long years, should she not have been released from this bond on the Sabbath day?” Luke 13:16 NASB). But Jesus turning to them said, “Daughters of Jerusalem, stop weeping for Me, but weep for yourselves and for your children (Luke 23:28 NASB). Please note Jesus did not tell the woman who was weeping and washing His feet to stop, she too was of the seed of Abraham (Through faith). The Daughters of Jerusalem were not. They were the “Other” children of the flesh, descendant’s of Abraham.
The woman referred to as a Daughter of Abraham is one of God’s Elect ones, the promise to Abraham that in his seed all the earth would be blessed (For assuredly He does not give help to angels, but He gives help to the descendant of Abraham Hebrews 2:16 NASB). Being descendants of Abraham doesn’t make them truly Abraham’s children. For the Scriptures say, “Isaac is the son through whom your descendants will be counted,” though Abraham had other children, too (Romans 9:7 NLT).
It is not those born of the flesh that are given the promise, it is through Isaac the promise came, the seed of Abraham. Jesus knew this woman was of the Godly line (Sons of God) from Abraham. Those the Lord called: “Daughters of Jerusalem” were not of the seed (Promised ones from Isaac) of Abraham. Now we can understand the term: “Sons of God” being those chosen of God and the: “Daughters of men” not the Godly line of faith. The Lord refutes this belief that Angels had sexual relations with humans. Also, if that were true, Jesus could not represent fallen Adam, the descendants would have been changed by a new “created” sperm (How could the fallen Angels through Satan duplicate God’s creation of Adam and the seed he passed on to all humanity? They can’t!) “For in the resurrection they neither marry nor are given in marriage, but are like angels in heaven (Matthew 22:30 NASB).
I have included a link below that goes into greater detail regarding this subject.