On this mountain…the Lord will destroy the web that is woven over all the nations and remove from the face of the earth the reproach of his people. The Mountain of the Lord (also called the mountain of the Lord’s house) is a concept that features prominently in the Hebrew Scripture. It is often identified with Jerusalem (both the real and apocalyptic one), and for a good reason. Jerusalem is the city of God, a place where God chose to make his throne dwelling. Anybody who wanted to meet and converse with God had to make it to Jerusalem (temple). In the Messianic (apocalyptic) literature, Jerusalem retains this prominence. Just as God had chosen Jerusalem to be his dwelling place, so it is in Jerusalem where the ultimate salvation by the Lord God will take place. While it is not clear whether it is the present Jerusalem that will be transformed to match the needs of the time (hence the title New Jerusalem), or whether it is the concept that will endure, there is one thing that remains clear: Jerusalem it will be. 
Of the many features of the Messianic Jerusalem that the Scriptures celebrate is the fullness of life. Many nations will stream to this place because of the many good things that are found therein. The New Jerusalem will become the home for the new creation that will result from the re-creation of the universe by God. The New Jerusalem will become the New Capital of the world. The peoples of the earth will be made into a single nation, and men and women will be able to look God in the face with no fear of dying (the ancient curse [cf. Exodus 33:20]). For Christians, the understanding is that in Jesus Christ, this movement towards the fullness of life has already begun. Jesus Christ is the New Jerusalem because God has chosen to reveal the self in him. As the fullness of the revelation of God, Jesus Christ has already done away with the ancient curse and has enabled creation to look at the face of God without dying. In Jesus Christ, we have already been given access to the fullness of life that is found only in God. His second coming for which we all long will thus be the culmination of what has already begun. When we therefore anticipate in celebration his second coming, we do so in the knowledge that he is coming to lead us to the source of the fullness of life.