Why did God make the earth with a "deep"?
According to Scripture, God divided the deep--"And God said, Let there be a firmament in the midst of the waters, and let it divide the waters from the waters" (Genesis 1:6). He then gathered the waters under the firmament in one place--"And God said, Let the waters under the heaven be gathered together unto one place, and let the dry land appear" (Genesis 1:9). God flooded the land with these gathered waters as an act of judgment--"In the six hundredth year of Noah's life . . . were all the fountains of the great deep broken up" (Genesis 7:11). Thus, when God created our universe, He wove into its very fabric the means of judgment.
Is it right to connect these events consequentially? Yes, the apostle Peter did: "By the word of God the heavens were of old, and the earth standing out of the water and in the water: Whereby the world that then was, being overflowed with water, perished" (2 Peter 3:5-6). Thus, the New Testament testified to God's plan (from creation) to judge sin.
The "deep" attests not only to God's justice, but also to His mercy: "And I saw a new heaven and a new earth: for the first heaven and the first earth were passed away; and there was no more sea" (Revelation 21:1). "No more sea" implies no more judgment. Thus, in the universe to come, God deliberately omits from its fabric the means of judgment.
Why? "For he hath made him to be sin for us, who knew no sin; that we might be made the righteousness of God in him" (2 Corinthians 5:21). Christ has taken away our sin--and the reason for our judgment. What glorious truth! NTJ
http://www.icr.org/article/6961/