Question: Does Luke 3 not prove that the sons of Elohim in Genesis 6 are the sons of Seth¹?

And Yahushua Himself began to be about thirty years of age,
being (as was supposed) the son of Joseph, which was the son of Heli, Which was
the son of Matthat, which was the son of Levi, which was the son of Melchi,
which was the son of Janna, which was the son of Joseph, Which was the son of
Mattathias, which was the son of Amos, which was the son of Naum, which was the
son of Esli, which was the son of Nagge, Which was the son of Maath, which was
the son of Mattathias, which was the son of Semei, which was the son of Joseph,
which was the son of Juda, Which was the son of Joanna, which was the son of
Rhesa, which was the son of Zorobabel, which was the son of Salathiel, which
was the son of Neri, Which was the son of Melchi, which was the son of Addi,
which was the son of Cosam, which was the son of Elmodam, which was the son of
Er, Which was the son of Jose, which was the son of Eliezer, which was the son
of Jorim, which was the son of Matthat, which was the son of Levi, Which was
the son of Simeon, which was the son of Juda, which was the son of Joseph,
which was the son of Jonan, which was the son of Eliakim, Which was the son of
Melea, which was the son of Menan, which was the son of Mattatha, which was the
son of Nathan, which was the son of David, Which was the son of Jesse, which
was the son of Obed, which was the son of Booz, which was the son of Salmon,
which was the son of Naasson, Which was the son of Aminadab, which was the son
of Aram, which was the son of Esrom, which was the son of Phares, which was the
son of Juda, Which was the son of Jacob, which was the son of Isaac, which was
the son of Abraham, which was the son of Thara, which was the son of Nachor, Which
was the son of Saruch, which was the son of Ragau, which was the son of Phalec,
which was the son of Heber, which was the son of Sala, Which was the son of
Cainan, which was the son of Arphaxad, which was the son of Sem, which was the
son of Noe, which was the son of Lamech, Which was the son of Mathusala, which
was the son of Enoch, which was the son of Jared, which was the son of
Maleleel, which was the son of Cainan, Which was the son of Enos, which was the
son of Seth, which was the son of Adam, which was the son of Elohim. (Luke 3:23-38)

Answer: No.  Luke’s genealogy actually proves just the opposite.  Seth is referred to as "the son of Adam," not the "son of Elohim."  Consequently, all of Seth’s descendants were sons/daughters of Adam (sons/daughters of men).  Adam, alone, is referred to as the "son of Elohim" in this passage.²

In Genesis 6, the daughters of men are contrasted with the sons of Elohim³.  The word translated as "men" here is ‘Adam (H120/H121), which denotes the first man, Adam, and by implication all of mankind after him.

And it came to pass, when men began to multiply on the face of the earth, and daughters were born unto them, That the sons of Elohim saw the daughters of men [H120/H121 – ‘Adam] that they were fair; and they took them wives of all which they chose. (Genesis 6:1-2)

There are two mutually exclusive groups presented here.  To which group do Seth’s descendants belong?

1. The sons of Elohim (or)
   
2. The daughters of Adam

Luke’s genealogy states clearly that Seth was the "son of Adam."  This irrefutably places the descendants of Seth (the woman in particular) in the second group: The daughters of Adam.⁴  Thus, Luke 3 proves that the "sons of Seth" are not the "sons of Elohim."

Related Content: Nephilim (Giants) in the Bible: Is Yahuwah a Genocidal Maniac or a Loving Creator?

¹ The Sethite theory posits that the "sons of Elohim" in Genesis 6 are the descendants
of Seth and the "daughters of men" are the descendants of Cain.  This
theory suggests that through the intermarriage of Seth’s righteous
descendants and Cain’s wicked descendants, the world became irreparably
corrupted.  Consequently, Yahuwah was forced to flood the world and
begin again with righteous Noah and his family. 

² Adam had no earthly father.  He was created by Elohim. (See Genesis 1:26-28.)

³ "Sons of Elohim" (B’nai HaElohim)
is always indicative of angels

in the Old Testament. (See Job 1:6; Job 2:1; Job 38:1-7.)

⁴ There is absolutely nothing in the phrase "daughters of men
[‘Adam]" that is specific to a particular earthly family.  "Daughters of
men [‘Adam]" is simply a general reference to the female descendants of
Adam, i.e. female human beings.