In the book of Revelation in the New Testament, John also mentions a "new Jerusalem" of the last days: "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. And I John saw the holy city, new Jerusalem, coming down from God out of heaven, prepared as a bride adorned for her husband." (Revelation 21:1-2.)
President Joseph Fielding Smith wrote the following concerning this holy city referred to by John:
The prevailing notion in the world is that this is the city of Jerusalem, the ancient city of the Jews which in the day of regeneration will be renewed, but this is not the case. We read in the Book of Ether that the Lord revealed to him many of the same things which were seen by John. . . . In his vision, in many respects similar to that given to John, Enoch saw the old city of Jerusalem and also the new city which has not yet been built, and he wrote of them as follows . . . [see Ether 13:2-11].In the day of regeneration, when all things are made new, there will be three great cities that will be holy. One will be the Jerusalem of old which shall be rebuilt according to the prophecy of Ezekiel. One will be the city of Zion, or of Enoch, which was taken from the earth when Enoch was translated and which will be restored; and the city Zion, or New Jerusalem, which is to be built by the seed of Joseph on this the American continent.
"And righteousness will I send down out of heaven; and truth will I send forth out of the earth, to bear testimony of mine Only Begotten; his resurrection from the dead; yea, and also the resurrection of all men; and righteousness and truth will I cause to sweep the earth as with a flood, to gather out mine elect from the four quarters of the earth, unto a place which I shall prepare, an Holy City, that my people may gird up their loins, and be looking forth for the time of my coming; for there shall be my tabernacle, and it shall be called Zion, a New Jerusalem.
"And the Lord said unto Enoch: Then shalt thou and all the city meet them there, and we will receive them into our bosom, and they shall see us; and we will fall upon their necks, and they shall fall upon our necks, and we will kiss each other;
"And there shall be mine abode, and it shall be Zion, which shall come forth out of all the creations which I have made; and for the space of a thousand years the earth shall rest." [Moses 7:62-64.]
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. (Answers to Gospel Questions 2:103, 105, 106.)