8:22 “While the earth remaineth, seedtime and harvest, and cold and heat, and summer and winter, and day and night shall not cease. “
Immediately following the Flood, the Earth was a very different place from what it had been just a few short months earlier. The Oceans were more extensive, and therefore, there was less land surface than before the Flood.
The land was nearly barren of vegetation and devoid of animal life. The mist that enveloped the air and watered the vegetation was gone. The formerly even and temperate world climate had more radical swings.
Seasons became more pronounced, and as a result, more important because the growth of plants for food depended on temperature, and certain amounts of sunlight to be present.
And, most dramatically, only 8 people and a handful of animals were left to inhabit, and then to repopulate, the entire surface of the earth.
9:1 “And God blessed Noah and his sons, and said unto them, Be fruitful, and multiply, and replenish the earth.”
Noah, just like us, was born with a fallen nature into a fallen world. Because Noah trusted and obeyed God, God simply declared Noah righteous.
This most fundamental principle of Salvation……trusting God and being credited (as opposed to earning) righteousness…… is the same exact principle that we all count on today; and it is present right here, a second time in the OT, in Genesis, first with the mercy shown to Adam and now to Noah.