The flood

The idea of the flood, as described in Scripture, is widely mocked but there is no reason why that should be so. A careful reading of what the Bible actually says and what science actually reveals would point up no obvious contradiction. For example thousands of fossils of deep sea creatures have been found in the Austrian Alps, presumably left there following the flood. Generally speaking most fossils are better explained by a great flood than by evolution.

As for Noah's ark, there is no reason to doubt the story as long as we remember how very large the ark was, the need for only a limited number of species to be on board (eg all varieties of dog known today coming from the original pair) and the fact reptiles and dinosaurs go on growing and so only babies were necessary not huge examples of grown adults.

Ante-diluvian life

It is clear from Genesis 4 that what we tend to think of as civilisation came in at a very early point. Even before the flood people were lving in cities, music was a common and varied thing. The use of technology aso came in early on - making tools in bronze and in iron.

It is well known that before the flood people lived to great ages - though no-one ever reached a thousand years. Such claims are literal and no doubt facilitated great advances in a life time. Some of theseearly people became truly great. They were heroes of old, achieving more than was easily possible after the flood. The cause is not clear but the flood clearly brought in great changes that considerably lessened longevity.

Although sacrifices took place pre-flood, it is possible that society was vegetarian.

The beginning of the worship of God is noted at the end of Chapter 4. The beginning of the godly and messianic line is alos noted there. One reason for the flood was the co-mingling of the two lines - the godly and the ungodly.

Why not start again?

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.