Bavinck:

But this first period in the history of humankind also soon became marked by the most fearsome wickedness. The corruption of the best proved the worst; the extraordinary powers and gifts were abused in the service of sin. This period was ushered in with fratricide. The Cainites, separating themselves from the Semites, concentrated on dominating the earth (Gen. 4:20ff.) and found their strength in the sword (Gen. 4:24). But only when the two, the Sethites and the Cainites, intermingled did wickedness explode: the imagination of the thoughts of their hearts were continually only evil (Gen. 6:5). It was a period so full of iniquity as would never come again until its return in the days of the Son of Man (Matt. 24:37). In a calamitous flood this whole generation disappears, except for Noah’s family, which then becomes the nucleus of a second humanity. The period after the flood is essentially different from that before the flood. In the time from Adam to Noah, nature–the world of plants and animals–as well as humankind bore a very different character from that of the time following. Powerful and copiously supplied with gifts, the world was, as it were, left to itself for a time; but it soon became evident that if God did not forcefully intervene, the world would perish in its own wickedness. With Noah, therefore, a new period begins. The grace that manifested itself immediately after the fall now exerted itself more forcefully in the restraint of evil. God made a formal covenant with all his creatures This covenant with Noah (Gen. 8:21-22; 9:1-17), though it is rooted in Gods grace and is most intimately bound up with the actual covenant of grace because it sustains and prepares for it, is not identical with it. It is rather a “covenant of long-suffering” made by God with ad humans and even with all creatures. It limits the curse on the earth; it checks nature and curbs its destructive power; the awesome violence of water is reined in; a regular alternation of seasons is introduced The whole of the irrational world of nature is subjected to ordinances that are anchored in God’s covenant. And the rainbow is set in the clouds as a sign and pledge (Gen. 8:21-22; 9:9-17).

A humanity now appears that, by comparison with the preceding one, is much gentler in nature, diminished in power, and of a much shorter life span. The blessing of multiplication is again expressly stated (Gen. 9:1); the fear and the dread of humans is laid on every animal (v. 2); green plants and meat are given to humans for food (v. 3). Human life is safeguarded by the requirement of the death penalty for murder and by implication, in principle, by the institution of government (w. 5-6). And later when humanity in building the tower of Babel conceives a plan to continue to live together in one location and to start a world empire, God frustrates the plan, disperses it in peoples and languages, and in that way, too, counters the development and explosion of wickedness! The grace of God, accordingly, manifests itself much more forcefully after the flood than before. To it is due the existence and life of the human race; the expansion and development of peoples; states and societies, which gradually came into existence; religion and morality, which were not completely lost even among the most degenerate peoples; and the arts and sciences, which achieved a high level of development. Everything that after the fall is still good even in sinful humans in all areas of life, the whole structure of civil justice, is the fruit of Gods common grace. Granted, God did allow the Gentiles to walk in their own ways (Acts 14:16), but he did not leave them; he did not leave himself without witnesses to them but revealed himself to them through the works of his hands (Acts 14:16-17; 17:27-28; Rom. 1:19; James 1:17). The Logos illumines every human coming into the world (John 1:9). The Holy Spirit is the author of all life, power, and virtue, also among the Gentiles (Gen 6-17- 7:15; Pss. 33:6; 104:30; 139:2; Job 32:8; Eccles. 3:19). Humankind was led by this grace and under the dispensation of this covenant of nature before Christ and prepared for his coming. One can indeed speak in a positive sense of mankind’s education by God. A susceptibility for salvation was maintained and the need for it aroused.

Herman Bavinck, Reformed Dogmatics, (Grand Rapids, Michigan: Baker, 2004), 3:217-219. [Original footnotes not included, and underlining mine.] [For more on Bavinck and Common Grace, see his excellent article, Calvin and Common Grace.]