Gen6: Humankind corrupted the earth with evil. God decided to destroy them. He told Noah to build an ark to be saved from the flood.
Gen7: Noah and his family went into the ark with two of each creature. It rained for forty days and forty nights and the earth was covered.
Gen8: The flood abated. Noah sent out a raven and two doves. When the earth was dry God called them all out of the ark. Noah built an altar.
Gen9: God blessed Noah and set the rainbow as a sign that he would never flood the earth again. Noah got drunk and cursed Ham’s son Canaan.
The Flood illustrates how man cannot survive with it’s conscious alone. God created man without giving him a Ten Commandments or any other revealed moral instruction. The only moral code was the one God built in to the human being: the conscience. The world sank into evil. Even today secular world holds that religion and God are morally unnecessary; the individual’s conscience is sufficient to guide moral behavior. The Bible, as usual, knew better.
The world sank into sin. During this time the devil had a plan to corrupt the blood of man to stop Jesus from being born. So he had the fallen angels (Sons of God) take the woman (daughters of Adam) as they please, creating Nephilim (Hercules, zoose, ect.)
Noah was perfect in his blood and also walked with God so God instructed him to create an Ark and to his family along with animals paired to avoid a flood that is coming.
After 7 days, according to the Hydro Plate theory, the firmament fell along with the waters from the earth for 40 days and 40 nights causing Noah to float for 110 days after the rain stopped. The ark arrived on Mt. Ararat and Noah waited another 4 months before sending out a Raven and a Dove. The Dove came back because it had no sign of land. On the second time the dove returned with an olive twig and did not return on the 3rd time. After 7 more days Noah left the ark and God made a promise to never flood the Earth again using a Rainbow as a covenant.