The sons of God are not fallen angels, they did not produce some half-man, half-angel
Q. Are the "sons of God" in Genesis 6.2 fallen angels?
A. This issue comes up every so often and we’ll deal with it again here.
The "sons of God" are not fallen angels and they did not produce some sort of half-man, half-angel type of being.
Let’s start in Genesis 6.1 and work through verse 4.
Chapter 6 is telling us of Satan’s further attempt to corrupt mankind.
There are other attempts in scri pture like when Balaam and Barak caused Israel to sin and 24,000 died.
As mankind procreated, daughters were born.
As time went on some followed after God and others didn’t and the truth was being corrupted.
The "sons of God" is merely an expression for the believing line, also called the "sons of Seth" based on Genesis 4.26.
In Genesis 6.2 these sons of Seth began to choose wives from the daughters of men from "whomever they chose" out of the unbelievers and they were unequally yoked.
Remember Abraham had a fear of this when he wanted to choose a wife for Isaac and the wives of Jacob and Esau is another example. The Lord saw this wasn’t good.
Living long lives was not producing repentance (2 Pet 3.9) and He sets a certain time limit (2 Cor6.2) in Genesis 6.3.
The Nephilim in verse 4 were the children produced by these parents.
Nephilim in Hebrew simply means "fallen ones" which implies that they had fallen from the truth with ferocity and impiety.
This word is used again in Num 13.33 with allusions to the "giants in Deut 1.18, 2 Sam 21.18-22, 1 Chr 20.4-8 and these certainly were not children born from fallen angels but simply people with a "giant" reputation of ferociousness and impiety who had fallen away from the truth.
These people became famous for their valor, power and rule and certainly the battle between David and Goliath would be an example of this struggle between the truth and those who had fallen away (nephilim) that has been going on since Genesis 6.
There "nephilim" in the world today, too.
Now there are several other reasons why these were not fallen angels. First, angels cannot marry or are they given in marriage (Mt 22.29-32).
Secondly, angels can’t produce children with humans because they don’t have the DNA to do it.
Mankind can only produce "after their own kind" and that is through the DNA so that should settle this whole issue right there.
So, in conclusion, Genesis 6 begins to tell the story of how the truth of God begins to get corrupted and believers began to intermarry with unbelievers producing a mixture of truth and error.
In time mankind was so corrupted that God brought the flood and preserved the truth through the righteous line of Noah.
Later through the line of Shem ("semites") the Messiah would be born who would destroy Satan as promised in Genesis 3.15.
Genesis 6 tells us the story of how God preserved the truth of His Word to save mankind and judged those who had fallen from the truth and corrupted themselves through unbelief.