The descendants of Seth were called the sons of God and the descendants of Cain were called the sons of men.
The descendants of Seth were called the sons of God; the descendants of Cain, the sons of men. As the sons of God mingled with the sons of men, they became corrupt and, by intermarriage with them, lost, through the influence of their wives, their peculiar, holy character, and united with the sons of Cain in their idolatry. Many cast aside the fear of God and trampled upon His commandments. But there were a few that did righteousness, who feared and honored their Creator. Noah and his family were among the righteous few. Cc36.6
Genesis 6:1 And it came to pass, when men began to multiply on the face of the earth, and daughters were born unto them,
6:2 That the sons of God saw the daughters of men that they [were] fair; and they took them wives of all which they chose.
The sons of God saw how beautiful the daughters of Cain were and they took them as wives but through the influence of their wives they were corrupted. The sons of God lost they’re godly character and they joined in the general apostasy. Until at last, there was only a few who remained worshipers of God. There was Methuselah and some others who died before the flood and there was Noah and his family. These were the only ones left. Read the rest of this entry