Thank you for the interpretative question on Genesis 1:6–9, “The Book of Genesis states that there is a space that cuts the waters into two parts. The first part: the oceans. The second part: the cosmos (they must’ve believed that the cosmos is water). What’s in the middle is the atmosphere. Right or wrong?”
There are various interpretations on Genesis 1:6–9. Instead of me stating the various viewpoint, here is one viewpoint for one’s consideration.
A. Genesis 1:2 states that the Spirit of God was hovering over the waters. At this point of the description of the water, there is a body of water that seems to surround the earth.
B. Genesis 1:3 states that God declare let there be an expanse between the waters to separate water from water. There is water beneath the expanse and there is water above the expanse. “So God made the expanse and separated the water under the expanse from the water above it” (vs. 6–7).
C. Genesis 1:7 states that God the expanse “sky” or what is called the atmosphere around the earth. The atmosphere is not without moisture for with the sky there is H20 as we called it.
D. Genesis 1:9 states that God called the gathered water so that the land could appear as being “seas”. Thus prior to this point, the water was still surrounding the earth before the land mass appeared. As the land mass appeared, the water receded whereby the land mass divided the waters.
E. Genesis 1:9 does not state what God called the water above the expanse. There is no name for it. Why there is no name for it is unclear. The text is silent on that point.
F. Genesis 6:11 God states that he opened all the springs of the great deep burst forth and the floodgates of the heavens were opened. Thus up to this point rain had not fallen on the earth. The phrase, floodgates of the heaven were opened would mean more than the water in the sky but the water above the sky. That water from above and the water in the crust of the earth flooded the earth.
The Scripture does not state the dimension of the waters above the earth or on earth below and yet man is able to see the sun, moon, and stars.
It is my understanding of the text that there was a body of water above the sky that poured onto earth leaving the sky as we understand it today. This body of water surrounded the earth and protected it from the harmful sun ray as we know it today. With the destruction of the heavenly body of water above the earth, decay accelerated on earth.
SUMMARY: Genesis describes the earth with three layers of water: the seas, the expanse/sky and the “heavenly” water above the expanse. The Flood removed the heavenly water which affected what is known as climate change on earth. Thus today there is only the sky and the seas/ocean.
For more perspectives: