The question arises because the “new earth” mentioned in Revelation 21:1 receives no further mention in the remainder of the paragraph while the concept of “Jerusalem” pervades the coming verses. The implication would be that the “new earth” is all (metaphorically) “city,” “Jerusalem,” where God dwells with his innumerable people. In this paragraph, then, the “new Jerusalem” is equivalent to the “new earth.”
2 And I saw the holy city, new Jerusalem, coming down out of heaven from God, prepared as a bride adorned for her husband.