The Noahic Covenant
"While the earth remains, seedtime and harvest, cold and heat, summer and winter, day and night, shall not cease" (8:22).
Adam and Eve were bound to keep the covenant of works and thus merit eternal life for themselves and all their descendants (Gen. 2:15-17). However, our first parents did not pass their test in Eden but failed their probation when they believed the serpent's lie that they could make themselves like God by eating of the forbidden tree (Gen. 3). At this point, the Lord would have been entirely within His rights to destroy Adam and Eve and start the whole project of creation over from scratch. Yet He did not do that. Without setting aside the covenant of works, our Creator mercifully made another covenant that would serve as a framework for His dealings with men and women who turn from their sin. This is the covenant of grace, which provides for the redemption of Adam's fallen children through the Messiah who keeps the covenant of works on our behalf and crushes the serpent (v. 15; Rom. 5:16-17). History is the story of the outworking of the covenant of grace.
God's covenant of grace was not revealed all at once in the garden of Eden, but rather unfolded in a series of covenants with Noah, Abraham, Moses, David, and Jesus. Today we are looking at the first sub-covenant to fall under the umbrella of the covenant of grace: the Noahic covenant. The Lord established this covenant in the context of a creation that had become increasingly rebellious and corrupt after the fall (Gen. 4:1-6:7). Humanity's wickedness was so great that God destroyed nearly every living thing in existence at the time.
After Adam and Eve's exile from Eden, Genesis 4:1-6:7 describes a creation that becomes increasingly corrupt as sin multiplies on the earth. Wickedness of all sorts was prevalent, prompting God to destroy creation with a flood. The only creatures to survive the flood were Noah's family and representatives of every animal that inhabited the earth (6:8-8:19). By this we see that the Lord saved a remnant, not all that He had made, and we should keep that in mind when we reflect upon the scope of God's saving work. He will not save everyone. Universalism is a false doctrine.
In the covenant with Noah, the Lord promised never again to destroy all life with a flood (8:20-9:17). He also pledges to sustain the seasonal cycle, and thus the general stability of nature. In this predictable order, people will flourish, and an arena will exist for Him to enter history via the incarnation of Christ and save His people (John 1:14).
Coram Deo
God's covenant with Noah provides an arena for His special grace to operate for the sake of our salvation, but this covenant is also the fruit of His common grace for all people. Everyone benefits from the regularity of nature, for it allows human society to flourish. We do not deserve this, and in preaching the gospel to others we should call their attention to the grace God has shown even while calling them not to presume upon His grace, but to repent that they would be saved.