Prelude to the Flood: Genesis 4-6
In the first part of chapter 4, we read the account of the sacrifices offered by Cain and Abel. Abel offers what God asked for (Hebrews 11:4 + Romans 10:17), but Cain offers something different. God accepts Abel and his offering, but not Cain or his offering, and Cain sulks. Then, Genesis 4:8 tells us, Cain murdered his brother Abel. When confronted by God, unlike his parents, Cain at first denies his guilt, 4:9. Cain was evidently a self-centered and immoral man.
Of course, Cain can't hide anything from God, and God lets him know that, as we can see in verses 10 and 11. In His mercy, God gives Cain another chance, setting a mark on him in order that he might not be killed. (Remember, at this point in time, everyone on earth is still pretty closely related to everyone else; therefore, any one of them is likely to want to avenge the murder of Abel.) Cain moves to Nod, and we learn a little about his descendants. Among his descendants are men skilled in raising livestock (4:20), making music (4:21), and working in metals (4:22). However, nothing is said of their moral character until we get to a man named Lamech, who is a bigamist, a murderer, and even boasts of his own wicked deeds (4:23-24). So, the general impression of the family of Cain is one of complete immorality.
This is especially true when contrasted with the descendants of Cain's brother, Seth. Seth's descendants are characterized by faithfulness to God, 4:26. In fact, one of Seth's descendants was so pleasing to God that he never died - God simply took him (5:24; Hebrews 11:5). Then, of course, comes the most famous name in the genealogy of Seth: Noah.
With these facts in mind, we have what appears to be two distinct groups of people on the earth: those who believe in God and obey Him (Seth's family), and those who do not really care about God (Cain's family). So, when we come to 6:1-2, and we see the "sons of God" intermarrying with the "daughters of men," it is not difficult to understand what is going on. Those who feared God intermarried with those who didn't, and the result was predictable: a generation of people who had no regard for God whatsoever. People had become thoroughly wicked, with absolutely no good intentions whatever, according to 6:5. As a consequence, the earth is described as "filled with violence" in 6:11. For this reason, God decides to destroy mankind (6:3,7).
All mankind, that is, except for Noah and his family. We must be impressed by Noah. Imagine how difficult it must have been to remain faithful to God, and to raise his sons to fear God, when literally everyone around him was bent on doing evil. Moreover, Noah was not content to simply do what was right and let everyone else sin; he tried to teach them and warn them of their situation (II Peter 2:5).
God decides to destroy mankind by means of a flood, as He tells Noah in 6:17. He gives Noah instructions for the construction of a huge boat, and Noah follows them to the letter, 6:13-22. Because of this, Noah is held up as an example of faith in Hebrews 11:7. Once again, as in the case of Abel, we see that faith and obedience are inseparable. If we have the kind of faith that Noah had, the kind of faith scripture teaches us to have, we will obey God.
The Flood, Genesis 7:1-8:19
It is evident that God is with Noah throughout this ordeal. He told Noah the precise time to go into the ark (7:1), saw to it that the animals went into the ark (7:8-9), and even shut the door of the ark behind them (7:16). There was no chance that Noah, his family, or the animals in the ark would drown, because God was caring for them. However, they were the only land-based creatures on earth to survive.
The flood covered the entire surface of the earth, as is emphasized in 7:17-24. There were two sources of water: the fountains of the deep and the windows of heaven, 7:11. This language indicates enormous quantities of water gushing from underground while torrential rains came down from the sky. These rains lasted an entire forty days, 7:12, but the waters continued to rise for 150 days, after which the waters began to gradually decrease, 7:24 - 8:4. Noah and his family were on the ark for a full year and ten days before God told Noah to come out of it (7:11 + 8:14-15).
The Aftermath of the Flood, Genesis 8:20-9:17
It seems that one of the first things Noah did upon leaving the ark was to offer sacrifices to God, 8:20. Whereas these were burnt offerings, the stench of which was probably not very pleasant, we are told in 8:21 that God "smelled a soothing aroma," indicating that God was pleased by Noah's expression of worship. This points to an acknowledgement on the part of both Noah and God of the need for sacrifice.
God promises that He will never again destroy the earth by water, and He creates the rainbow as a sign of that covenant, 9:9-17. There have been many floods since the time of Noah, but never anything like the one in his time. God has kept His promise, as He always does.
God also gives Noah the animals for food, 9:2-3. This is a new thing; previously, God had given people fruits and vegetables (1:29). However, whereas Noah and his descendants (including you and me) are allowed to kill and eat animals, there is a penalty for killing a human. God ordains in 9:5-7 that anyone who kills a human forfeits his own life. The reason God gives is that man is made in God's image. There is nothing else in the physical creation that compares to a human being in importance, in the eyes of God. Therefore, if we willfully destroy a human life, the only fair and equal penalty is death. Nothing else but a human life is sufficiently valuable to pay for a human life.
The world after the flood provided Noah with a new beginning, a fresh start. In 9:1 God even repeats to Noah the blessing He gave to Adam and Eve. Noah left a corrupt and utterly sinful world when he stepped into the ark. He stepped out of the ark on to a cleansed earth, with no one left but the people who feared God. So the flood accomplished more than one purpose. It punished the wicked, to be sure. However, it also relieved the earth of their violence. And, it provided the one family who loved God with an opportunity to worship Him and serve Him without the oppressive influence of hordes of godless people. For all who fear God, the Genesis flood is a message of hope. For those who do not, it is a warning.