“There shall be a new heaven and a new earth.” All things are renewed; the old earth and its atmosphere, its “heaven,” are elevated to terrestrial condition (see commentary at Alma 40:11). A New Jerusalem will be physically built up at the same place where earth’s history began, the Garden of Eden, and a New Jerusalem will come down out of heaven (the peoples of Enoch and Melchizedek and others who joined them; see Moses 7:27), and the united cities called New Jerusalem will join the Old Jerusalem to serve as world capitals for the Savior’s millennial reign.
These Jerusalems, cities of holiness, full of people of holiness, will, after the millennial era, become one grand celestialized New Jerusalem.
Regarding this New Jerusalem, President Joseph Fielding Smith said: “After the close of the millennial reign we are informed that Satan, who was bound during the millennium, shall be loosed and go forth to deceive the nations. Then will come the end. The earth will die and be purified and receive its resurrection. During this cleansing period the City Zion, or New Jerusalem, will be taken from the earth; and when the earth is prepared for the celestial glory, the city will come down according to the prediction in the Book of Revelation.”37
For more details on the various stages of the Old and the New Jerusalems, see commentary at 3 Nephi 20:29–33, 46.38