21:1 new earth. The first two chapters of the Bible describe the first heaven and the first earth in their primeval “very good” created state. Now the last two chapters describe the new heaven and new earth, once again made “very good” by their Creator. Actually the word “new” here is not neos, meaning “novel” or “young,” but kainos, meaning “fresh” or “renewed.” That is, the new earth will be the old earth made new again by purging out all the age-long evidences of sin and the curse, decay, and death. The very “elements” will have been melted and dissolved in fervent heat (II Peter 3:10-12), then all brought together again by the Creator in a perfect world once again. Furthermore, the new heaven and the new earth will “remain before me, saith the LORD” (Isaiah 66:22), “wherein dwelleth righteousness” (II Peter 3:13), and “the former shall not be remembered, nor come into mind” (Isaiah 65:17).
21:1 passed away. Note that Christ’s prophecy, made long before (Matthew 24:35) will finally be fulfilled, the only entity surviving from that previous world being the eternal Word of God (Psalm 119:160).
21:1 no more sea. Evidently there will be no need in the eternal earth for “this great and wide sea” (Psalm 104:25), and all the world will be habitable by human beings. There will still be water, however, for the “pure river of water of life” will flow eternally from the throne of the Lamb (Revelation 22:1). There will also be waters “above the heavens” again (Psalm 148:4,6). The hydrology and meteorology of the new earth and its new atmospheric heaven will be, in many respects, like those of the Edenic world.