We find the setting for God’s judgment in the flood in Genesis 6:1–7: “When human beings began to increase in number on the earth and daughters were born to them, the sons of God saw that the daughters of humans were beautiful, and they married any of them they chose. Then the Lord said, ‘My Spirit will not contend with humans forever, for they are mortal; their days will be a hundred and twenty years.’
“The Nephilim were on the earth in those days—and also afterward—when the sons of God went to the daughters of humans and had children by them. They were the heroes of old, men of renown.
“The Lord saw how great the wickedness of the human race had become on the earth, and that every inclination of the thoughts of the human heart was only evil all the time. The Lord regretted that he had made human beings on the earth, and his heart was deeply troubled. So the Lord said, ‘I will wipe from the face of the earth the human race I have created—and with them the animals, the birds and the creatures that move along the ground—for I regret that I have made them.’”
Apparently, the most significant reason that God chose to bring about the flood is that the corruption of man’s heart completely dominated humanity in the days of Noah. God certainly knew that sending the flood would not (and did not) fix the sin problem in man’s heart; after the flood, God observes that “every inclination of the human heart is evil from childhood” (Genesis 8:21). In the same statement, God also says, “Never again will I destroy all living creatures, as I have done.”
So God sent the flood because of the evil on the earth at Noah’s time but thereafter promised not to send such a flood again—in spite of the fact that evil was still present. If God knew that evil would not be eradicated with the flood, why did He send the flood in the first place? We will look at three answers:
One way to answer why God sent the flood when He knew that evil would continue is to interpret mankind’s sin in the time of Noah as something unique and significantly more severe than what we see in the world today. Indeed, Genesis 6:5 tells us that “every inclination of the thoughts of the human heart was only evil all the time.” This is a powerful indictment of the condition of the human heart: not only does Scripture say that the thoughts of man’s heart were purely, exclusively evil, but that his heart was always like this. However much we may complain about the condition of our world today, we probably should not compare our current situation to that of Noah, simply because the evil in his day appears to have reached unimaginable levels. There was something unusually evil about the heart of man in the days of Noah, and the Lord knew the best course of action was to simply start over. This approach is surely somewhat speculative, but it is at least consistent with what we read elsewhere in Scripture about who God is.
Another possibility as to why God sent the flood when He knew that evil would continue takes a cue from the “sons of God” and “Nephilim” references in Genesis 6:2 and 4. Although Bible scholars are divided over exactly who the sons of God and Nephilim were, the Bible is clear that their descendants were characterized by some particularly extreme form of evil. Moreover, in Genesis 6:3 it seems that the Lord’s response to the actions of the sons of God is the first actual reference to the flood: by saying that “[man’s] days will be a hundred and twenty years,” God effectively begins the countdown for the onset of the judgment. This suggests that the flood was God’s direct response to the actions of the sons of God and the Nephilim.
Another possible answer for why God sent the flood when He knew that evil would continue is somewhat more general. First Corinthians 10:11 tells us that the stories in the Old Testament are useful as more than historical records: “These things happened to them as examples and were written down as warnings for us, on whom the culmination of the ages has come.” In the story of the flood is an example for us to heed. Jesus draws a parallel between the story of the flood and today in Matthew 24:37–39: “As it was in the days of Noah, so it will be at the coming of the Son of Man. For in the days before the flood, people were eating and drinking, marrying and giving in marriage, up to the day Noah entered the ark; and they knew nothing about what would happen until the flood came and took them all away. That is how it will be at the coming of the Son of Man.” The historical flood of Noah’s day, therefore, stands as a symbol of God’s coming judgment. Just as Noah’s contemporaries failed to understand their impending doom, many of our own contemporaries will be swept away in God’s judgment without ever comprehending their need for a Savior. The flood functions as a warning to those who would presume upon God’s mercy in continuing their disobedience; the flood calls all to repentance.
God sent the flood to judge the world at that time of heinous, continual, worldwide sin. Yes, He knew that the flood would not eradicate the sin problem and that mankind would remain sinful after the flood. But God was not done dealing with sin. He sent His Son into the world to disarm the powers of evil and make “a public spectacle of them, triumphing over them by the cross” (Colossians 2:15). Because of Christ, the new heaven and new earth are promised (Revelation 21:1), and “no longer will there be any curse” (Revelation 22:3).