Adam’s fall affected the entire human race because he was our federal representative before God. What he did is regarded by the Lord as what we did, for in Eden, Adam was chosen to stand before our Creator in our place. Thus, his guilt is imputed to all his descendants (except Christ), and the only way out of this state of sin is for another appointed representative to obey the Lord in our place and atone for our sin. That representative, of course, is the God-man Christ Jesus, who had to suffer, die, and be resurrected so as to take away our sin and provide for us a righteous status before our Maker (Rom. 5:12–21; see Mark 8:31).
That Adam’s sin would require a divine solution is made evident in the story of Noah. We see that in the generations following Adam and Eve, humanity descended further and further into wickedness. Murder was perhaps the most egregious example of degeneracy, but the disregard for the Lord was also exemplified when men who called on God’s name forsook Him to marry pagan women (Gen. 4; 6:1–4). Our Creator saw that the hearts of people were “only evil continually” (6:5). Human beings could not get it together but continued the slide into abject wickedness, and the Lord took action, wiping out all people except for Noah and his family (6:9–8:19).
But the flood would not be the divine solution to evil, for after Noah and his family left the ark, God took stock of humanity again and saw that people’s souls had not changed. After the flood, it was still true that “the intention of man’s heart is evil from his youth” (8:21a). In keeping with the Lord’s promise to send the seed of the woman to deal fully and finally with sin and Satan, the Lord would not end the story of humanity with the destruction of the flood.
Thus, God made a covenant with Noah and his descendants not to destroy the earth again with a flood (8:20–9:17). In this covenant, God pledged to preserve the earth and its seasons, keeping a stable environment in which people could live and have the opportunity to turn to Him. The Noahic covenant also includes certain laws that remain binding until the end of the age. Prominent among these is the command to institute capital punishment for what we would call first-degree murder (9:5–6). Such a command indicates the high value that God places on the lives of His image-bearers. It also reminds us of the gravity of sin. The Lord will not take sin lightly, and He demands that human society stand against evil as well.