From the moment of the fall of humankind there a definite decline sets in. First Cain murders his brother and very soon we have a man (Lamech) with two wives threatening multiple revenge for violence. By the time of Noah it has t be said that "every inclination of the thoughts of the human heart" has become "only evil all the time" Left to itself, this is always the drift of human society. The idea is bound to be raised, however, that if humankind simply started over again then all will be well. And so God rescues righteous Noah and his family and destroys all the rest.
Yet, no sooner is Noah through the ordeal than he has fallen into drunkenness and that leads to other problems too. Simply starting over is not the answer.
The flood also anticipates the final judgement - next time not water but fire.
The flood also anticipates the final judgement - next time not water but fire.
