For the glory of God's justice, and for warning to a wicked world, before the history of the ruin of the old world, we have a full account of its degeneracy, its apostasy from God and rebellion against him. The destroying of it was an act, not of an absolute sovereignty, but of necessary justice, for the maintaining of the honour of God's government. Now here we have an account of two things which occasioned the wickedness of the old world: - 1. The increase of mankind: Men began to multiply upon the face of the earth. This was the effect of the blessing (Gen 1:28), and yet man's corruption so abused and perverted this blessing that it was turned into a curse. Thus sin takes occasion by the mercies of God to be the more exceedingly sinful. Pro 29:16, When the wicked are multiplied, transgression increaseth. The more sinners the more sin; and the multitude of offenders emboldens men. Infectious diseases are most destructive in populous cities; and sin is a spreading leprosy. Thus in the New Testament church, when the number of the disciples was multiplied, there arose a murmuring (Act 6:1), and we read of a nation that was multiplied, not to the increase of their joy, Isa 9:3. Numerous families need to be well-governed, lest they become wicked families. 2. Mixed marriages (Gen 6:2): The sons of God (that is, the professors of religion, who were called by the name of the Lord, and called upon that name), married the daughters of men, that is, those that were profane, and strangers to God and godliness. The posterity of Seth did not keep by themselves, as they ought to have done, both for the preservation of their own purity and in detestation of the apostasy. They intermingled themselves with the excommunicated race of Cain: They took them wives of all that they chose. But what was amiss in these marriages? (1.) They chose only by the eye: They saw that they were fair, which was all they looked at. (2.) They followed the choice which their own corrupt affections made: they took all that they chose, without advice and consideration. But, (3.) That which proved of such bad consequence to them was that they married strange wives, were unequally yoked with unbelievers, Co2 6:14. This was forbidden to Israel, Deu 7:3, Deu 7:4. It was the unhappy occasion of Solomon's apostasy (Kg1 11:1-4), and was of bad consequence to the Jews after their return out of Babylon, Ezr 9:1, Ezr 9:2. Note, Professors of religion, in marrying both themselves and their children, should make conscience of keeping within the bounds of profession. The bad will sooner debauch the good than the good reform the bad. Those that profess themselves the children of God must not marry without his consent, which they have not if they join in affinity with his enemies.

When men began to multiply - It was not at this time that men began to multiply, but the inspired penman speaks now of a fact which had taken place long before. As there is a distinction made here between men and those called the sons of God, it is generally supposed that the immediate posterity of Cain and that of Seth are intended. The first were mere men, such as fallen nature may produce, degenerate sons of a degenerate father, governed by the desire of the flesh, the desire of the eye, and the pride of life. The others were sons of God, not angels, as some have dreamed, but such as were, according to our Lord's doctrine, born again, born from above, Joh 3:3, Joh 3:5,Joh 3:6, etc., and made children of God by the influence of the Holy Spirit, Gal 5:6. The former were apostates from the true religion, the latter were those among whom it was preserved and cultivated. Dr. Wall supposes the first verses of this chapter should be paraphrased thus: "When men began to multiply on the earth, the chief men took wives of all the handsome poor women they chose. There were tyrants in the earth in those days; and also after the antediluvian days powerful men had unlawful connections with the inferior women, and the children which sprang from this illicit commerce were the renowned heroes of antiquity, of whom the heathens made their gods."

And it came to pass, when men began to multiply upon the face of the earth,.... Either mankind in general, or rather the posterity of Cain, who were mere natural men, such as they were when born into the world, and as brought up in it, destitute of the grace of God, and of the knowledge and fear of him; and who in proportion much more multiplied than the posterity of Seth, because of the practice of polygamy, which by the example of Lamech, one of that race, might prevail among them:

and daughters were born unto them; not daughters only, but sons also, though it may be more daughters than sons, or it may denote remarkable ones, for their beauty or immodesty, or both; and chiefly this is observed for the sake of what follows.