Genesis 6:2

The sons of God. This phrase has been interpreted in various ways. Ancient Jewish commentators, the early church Fathers, and many modern expositors have thought these “sons” to be angels, comparing them with the “sons of God” of Job 1:6; 2:1; 38:7. This view must be rejected, because punishment soon to be meted out was for the sins of human beings (see v. 3), and not of angels. Further, angels do not marry (Matt. 22:30). The “sons of God” were none other than the descendants of Seth, and the “daughters of men,” of the godless Cainites (PP 81). God later spoke of Israel as His “firstborn son” (Ex. 4:22), and Moses called the people of Israel “children of the Lord your God” (Deut. 14:1).

They took them wives. These unholy alliances between Sethites and Cainites were responsible for the rapid increase of wickedness among the former. God has ever warned His followers not to marry unbelievers, because of the great danger to which the believer is thus exposed and to which he usually succumbs (Deut. 7:3, 4; Joshua 23:12, 13; Ezra 9:2; Neh. 13:25; 2 Cor. 6:14, 15). But the Sethites did not heed the warnings they surely must have received. Guided by sense attractions, they were not content with the beautiful daughters of the godly race, and often preferred Cainite brides. Moreover, the prevalence of polygamy seems to be suggested by the plural expression used, they took “wives.”