TT: sons of God

6 ^1-2 When the human race began to increase, with more and more daughters being born, the sons of God noticed that the daughters of men were beautiful. They looked them over and picked out wives for themselves.

³ Then God said, “I’m not going to breathe life into men and women endlessly. Eventually they’re going to die; from now on they can expect a life span of 120 years.”
⁴ This was back in the days (and also later) when there were giants in the land. The giants came from the union of the sons of God and the daughters of men. These were the mighty men of ancient lore, the famous ones.

sons of God. Firstly, no where in the bible it is stated that angels can procreate. I will stand firm in my argument that sons of God refers to men, not angels. 

We look deeper into the verse. God said "I am NOT going to breathe life into men and women." There must something really bad that happened that caused God to stop breathing life into men. He was breathing life such that men can live 1000 years. But something changed. What was it? Something sinful i suppose?

Lets take a look at Jesus's genealogy.

²³ Jesus, when he began his ministry, was about thirty years of age, being the son (as was supposed) of Joseph, the son of Heli, ²⁴ the son of Matthat, the son of Levi, the son of Melchi, the son of Jannai, the son of Joseph, ²⁵ the son of Mattathias, the son of Amos, the son of Nahum, the son of Esli, the son of Naggai, ²⁶ the son of Maath, the son of Mattathias, the son of Semein, the son of Josech, the son of Joda, ²⁷ the son of Joanan, the son of Rhesa, the son of Zerubbabel, the son of Shealtiel,^[a] the son of Neri, ²⁸ the son of Melchi, the son of Addi, the son of Cosam, the son of Elmadam, the son of Er, ²⁹ the son of Joshua, the son of Eliezer, the son of Jorim, the son of Matthat, the son of Levi, ³⁰ the son of Simeon, the son of Judah, the son of Joseph, the son of Jonam, the son of Eliakim, ³¹ the son of Melea, the son of Menna, the son of Mattatha, the son of Nathan, the son of David, ³² the son of Jesse, the son of Obed, the son of Boaz, the son of Sala, the son of Nahshon, ³³ the son of Amminadab, the son of Admin, the son of Arni, the son of Hezron, the son of Perez, the son of Judah, ³⁴ the son of Jacob, the son of Isaac, the son of Abraham, the son of Terah, the son of Nahor, ³⁵ the son of Serug, the son of Reu, the son of Peleg, the son of Eber, the son of Shelah, ³⁶ the son of Cainan, the son of Arphaxad, the son of Shem, the son of Noah, the son of Lamech, ³⁷ the son of Methuselah, the son of Enoch, the son of Jared, the son of Mahalaleel, the son of Cainan, ³⁸ the son of Enos, the son of Seth, the son of Adam, the son of God.

Firstly we see Adam as the son of God. Which is the crux of my argument.  So, we know Adam is the son of God. Jesus as the Son of God. Who else is considered the son of God?  Everyone who is considered holy and worthy in God's eyes.

We remember that Adam has 2 sons(living). One, Cain and another Seth. So we also remember that Cain was the guy who murdered his brother Abel.

We see in 1 John 3:1 in the King James Version (KJV).

3 Behold, what manner of love the Father hath bestowed upon us, that we should be called the sons of God: therefore the world knoweth us not, because it knew him not.

The newer versions of the bible, it is mentioned children of God. Loosely speaking children of God = sons of God. But with one distinction. sons of God is reserved in the bible for people who walk really closely with God. Namely Adam and maybe some of his decendants? 

So we see that Seth is holy, but not Cain. So we can actually say that Seth's linage is sons of God while Cain's linage is not! So, after so much then we can deduce that 

"the sons of God noticed that the daughters of men were beautiful."

the sons of God is talking about Seth's linage while the daughters of men comes from Cain's linage. (because remember that Cain lived.)