A global flood would truly have been a horrendous event. Certainly, if nothing more was said about it by God, Noah and his descendents would have wondered if something like it would ever occur again. No doubt, each time a dark cloud appeared over the horizon, memories of the Flood would return, and folks would be terrified that God was judging their behavior. It might even encourage men building arks wherever they settled as a kind of insurance policy against God’s terrible judgment of their sins.
Well, such things don’t occur to us today, nor did they in our history, even when the Noahic Flood was remembered and recognized as a legitimate part of human history. Why didn’t we fear for a repeat of such a thing? It is because we had God’s promise that he would never again judge us as he did during Noah’s days (Genesis 9:11-16). God used the rainbow as a sign between us and him that he would never again bring a global flood in judgment against mankind. We could look upon the rainbow and remember God’s promise to us, and God would look upon it and remember we are only flesh, prone to do evil.
What significance could this have for a local flood? Certainly there have been many devastating local floods. Some floods, like those caused by tsunamis, give little warning. Has God broken his promise to us? An argument could be made against him, if the local flood theory is true. Couldn’t it? Well, some local flood theorists believe that all humanity lived in the Mesopotamian Valley (something which is presumed, for there is no mention of such a valley before the flood), and although it is presumed the flood was local in scope, it was able to destroy everyone living there. Nevertheless, this theory seems quite odd, indeed. Why wouldn’t man migrate to other areas in the 1600-2000 years before the flood? Notice how Rich Deem puts it:
“The flood, although local in extent, was global in judgment, since all humanity lived in the same locale. It wasn’t until God confused the languages (Genesis 11) that people began to spread over the earth. So, God promised to never again execute universal judgment of humans by means of a flood.”
Not only has God commanded man to spread out and fill the earth, it seems to be a characteristic of some men to move away from crowed areas. If God confused man’s language in Genesis 11 in order that men obey his command to fill the earth, why wouldn’t he have done so in Genesis 4-6 if mankind refused to obey that command? It seems to me that this was one of God’s original priorities, pertinent to his overall plan for us. If God showed his displeasure in Genesis 11, why would he act differently in Genesis 4-6?
The history of Cain in Genesis 4 seems to show he was a wanderer—moving from place to place. Moreover, he assumed that people would find him no matter where he migrated and kill him for what he did to his brother, Able (Genesis 4:14), and God didn’t contradict Cain’s suspicion. Instead, God pronounced a curse on anyone who would attempt to take Cain’s life. So, God implied men would migrate away from the place where mankind was originally created. It is inconceivable in the extreme to believe that Cain and everyone else simply migrated from one end of the Mesopotamian Valley to the other and never once left the area.
Finally, one could ask why God told Noah that the animals would fear men from that point forward. This implies that animal behavior was much friendlier to mankind before the Flood, perhaps like a domesticated dog normally is. Yet, in Genesis 9:2 that behavior changed. Why would it change if only a local flood was in view? If animals of only the Mesopotamian Valley were affected, why would all animals, all over the world, be in fear of man? This doesn’t make sense, unless the flood was global in nature, affecting all animals, even fish, for billions of aquatic fossils have been found all over the earth from the mountaintops of the Himalayas to the geologic column making up the Grand Canyon. All flesh was affected by mankind’s behavior, so all flesh is in fear of him. God’s judgment fits our sin.