We know that is not true. The sons of God married the daughters of men.
Genesis 6:2 "that the sons of God saw the daughters of men, that they were beautiful and they took wives for themselves of all whom they chose."
Angels don't marry.
And just how do we know that?
The answer is that we don't know that.
Further, we're talking about evil angels. On which planet do demons follow the rules?
Further still, the Hebrew word translated in the KJV as "wives" is 'Ishshah' (Strong's H802). It's a generic term meaning 'woman'. It does not have to mean "wife".
- Gen 2:22 And the rib, which the LORD God had taken from man, made he a woman, H802 and brought her unto the man.
- Gen 2:23 And Adam said, This is now bone of my bones, and flesh of my flesh: she shall be called Woman, H802 because she was taken out of Man.
- Gen 2:24 Therefore shall a man leave his father and his mother, and shall cleave unto his wife: H802 and they shall be one flesh.
- Gen 2:25 And they were both naked, the man and his wife, H802 and were not ashamed.
- Gen 3:1 Now the serpent was more subtil than any beast of the field which the LORD God had made. And he said unto the woman, H802 Yea, hath God said, Ye shall not eat of every tree of the garden?
- Gen 3:2 And the woman H802 said unto the serpent, We may eat of the fruit of the trees of the garden:
- Gen 3:4 And the serpent said unto the woman, H802 Ye shall not surely die:
- Gen 3:6 And when the woman H802 saw that the tree was good for food, and that it was pleasant to the eyes, and a tree to be desired to make one wise, she took of the fruit thereof, and did eat, and gave also unto her husband with her; and he did eat.
- Gen 3:8 And they heard the voice of the LORD God walking in the garden in the cool of the day: and Adam and his wife H802 hid themselves from the presence of the LORD God amongst the trees of the garden.
- Gen 3:12 And the man said, The woman H802 whom thou gavest to be with me, she gave me of the tree, and I did eat.
- Gen 3:13 And the LORD God said unto the woman, H802 What is this that thou hast done? And the woman H802 said, The serpent beguiled me, and I did eat.
- Gen 3:15 And I will put enmity between thee and the woman, H802 and between thy seed and her seed; it shall bruise thy head, and thou shalt bruise his heel.
- Gen 3:16 Unto the woman H802 he said, I will greatly multiply thy sorrow and thy conception; in sorrow thou shalt bring forth children; and thy desire shall be to thy husband, and he shall rule over thee.
- Gen 3:17 And unto Adam he said, Because thou hast hearkened unto the voice of thy wife, H802 and hast eaten of the tree, of which I commanded thee, saying, Thou shalt not eat of it: cursed is the ground for thy sake; in sorrow shalt thou eat of it all the days of thy life;
And that's just the uses of the word in the first three chapters of the bible. It's used 780 times in total. The meaning of the word undermines your argument completely.
Lastly, the context seems to make it impossible to rationally come to any other conclusion other than that demons were attempting to pollute humanity to the point that the birth of a savior was impossible. God rescued Noah because he was "perfect in his generations", meaning that he and his family had no Nephilim blood and were thus pure human. God could, therefore, start the race over with his family and still be able to produce a valid sacrifice for sin. Thus, even the context of the narrative itself lends credence to the notion that whoever the sons of God were, they were not human. Which would also explain why their offspring were giants rather than normal children.
Resting in Him,
Clete