But mankind had become so corrupt that God was grieved, and He decided to end all flesh, bringing a flood upon the earth to destroy it completely. But because Noah also walked with God, he found favor in the eyes of God, and God told Noah what He was going to do, and that man had only 120 years to repent. God told Noah to build an Ark, with rooms, out of Gopher wood, and He gave him instructions how to build it and what size to make it.
(Genesis 6: 12 And God looked upon the earth, and, behold, it was corrupt; for all flesh had corrupted his way upon the earth. 13 And God said unto Noah, The end of all flesh is come before me; for the earth is filled with violence through them; and, behold, I will destroy them with the earth. 14 Make thee an ark of gopher wood; rooms shalt thou make in the ark, and shalt pitch it within and without with pitch. 15 And this is the fashion which thou shalt make it of: The length of the ark shall be three hundred cubits, the breadth of it fifty cubits, and the height of it thirty cubits. 16 A window shalt thou make to the ark, and in a cubit shalt thou finish it above; and the door of the ark shalt thou set in the side thereof; with lower, second, and third stories shalt thou make it. 17 And, behold, I, even I, do bring a flood of waters upon the earth, to destroy all flesh, wherein is the breath of life, from under heaven; and every thing that is in the earth shall die. 18 But with thee will I establish my covenant; and thou shalt come into the ark, thou, and thy sons, and thy wife, and thy sons' wives with thee. 19 And of every living thing of all flesh, two of every sort shalt thou bring into the ark, to keep them alive with thee; they shall be male and female. 20 Of fowls after their kind, and of cattle after their kind, of every creeping thing of the earth after his kind, two of every sort shall come unto thee, to keep them alive. 21 And take thou unto thee of all food that is eaten, and thou shalt gather it to thee; and it shall be for food for thee, and for them. 22 Thus did Noah; according to all that God commanded him, so did he.)
And Noah did all that God had commanded. It is important to note that he did all according as God commanded him.
God then made a covenant with Noah, and promised that Noah, his wife, his sons and their wives would be safe in the Ark. Noah also was to take into the Ark 7 pairs of every kind of clean animal and clean birds, and 2 pairs of every unclean animal and unclean birds. He was to gather of all the vegetation for all of them to eat. And Noah did according to all God commanded of him.
Seven days before God brought the rains upon the earth, He had Noah, all his family and all the animals enter into the Ark, and God shut them in; and the waters of the flood came upon the earth. The "floodgates" were opened and the rain fell upon the earth for 40 days and 40 nights, until even the tallest mountain was 15 cubits (22 feet) beneath the surface of the water, but the Ark floated on the water in safety while everything on the earth perished, for the water covered the earth 150 days. And God did not forget Noah (And God remembered Noah-- in the sense of giving constant care). He caused a wind to blow over the earth and the waters began to dry up. It took another 150 days for the water to decrease, and in the seventh month the Ark rested on the top of Mount Ararat. In the tenth month the tops of the mountains could be seen. Seven days after the tops of the mountains could be seen Noah sent forth a raven, and it flew about until the earth dried up. Seven days after he sent the raven forth, Noah sent forth a Dove which found no resting place and it returned to the Ark. So Noah waited another seven days and sent out a Dove which returned that evening with an olive leaf in its beak. Noah was 601 years old in that first month on the first day when the waters were dried up