In Revelation 21:1, the Greek word kainos, translated “new” in the term New Earth, means new “in the sense that what is old has become obsolete, and should be replaced by what is new. In such a case the new is, as a rule, superior in kind to the old.”
Paul uses the same word, kainos, when he speaks of a believer in Christ becoming “a new creation” (2 Corinthians 5:17). The believer is still the same person as before, but he or she has been made new. Likewise, the New Earth will be the same as the old Earth, but made new.
In our resurrection, God may gather the scattered DNA and atoms and molecules of our dead and decayed bodies. In the earth’s resurrection, he will regather all he needs of the scorched and disfigured Earth. As our old bodies will be raised to new bodies, so the old Earth will be raised to become the New Earth.
So, will the earth be destroyed or renewed? The answer is both—but the destruction will be temporal and partial, whereas the renewal will be eternal and complete.
~ Randy Alcorn, [50 Days of Heaven]