6:1 multiply. God had commanded Adam and Eve to “multiply” (Genesis 1:28). With each man and woman enjoying hundreds of years of parental productivity plus almost ideal environmental and climatological conditions, the earth could well have been “filled” with people long before the Flood. For example, an initial population of two people, increasing at the rate of 2% annually (estimated to be the annual growth rate at present) would generate a population of well over ten trillion people in 1656 years (the time span from Adam to the flood).
6:2 sons of God. The identity of these “sons of God” has been a matter of much discussion, but the obvious meaning is that they were angelic beings. This was the uniform interpretation of the ancient Jews, who translated the phrase as “angels of God” in their Septuagint translation of the Old Testament. The apocryphal books of Enoch elaborate this interpretation, which is also strongly implied by the New Testament passages (Jude 6, II Peter 2:4-6; I Peter 3:19,20). The Hebrew phrase is bene elohim, which occurs elsewhere only in Job 1:6; 2:1; 38:7. In these three explicitly parallel usages, the contextual meaning can be nothing except that of angels. A similar phrase bar elohim, occurs in Daniel 3:25, and another, bar elim, occurs in Psalm 29:1 and Psalm 89:6. All of these also refer explicitly to angels. The intent of the writer of Genesis 6 (probably Noah) was clearly that of introducing a monstrous irruption of demonic forces on the earth, leading to universal corruption and eventual judgment.
6:2 took them wives. The “taking” of these women most likely refers to fallen angels, or demons, “possessing” their bodies. The word “wives” (Hebrew ishshah) is better translated “women.” There is no necessary intimation of actual marriage involved. By this time in history, anarchism and amorality were so widespread that these demons were easily able to take possession of the bodies of multitudes of ungodly men; these in turn engaged in promiscuous sex with demon-possessed women, with a resulting rapid population growth, Satan perhaps hoping thereby to generate a vast army of human recruits to his rebellion and also to thwart the coming of God’s promised Seed by thus corrupting all flesh.