Many Scriptures tell us that this present earth will be destroyed with fire and God will create new heavens and a new earth (See 2 Pet. 3:7-10, Rev. 21:1, Isa. 65:22, Matt. 24:35). Seventy percent of Earth is covered with water, but the New Earth will not have any oceans (Rev. 21:1). The "heavens" that God will create are a new atmospheric heaven and a new universe.
The heavenly city (New Jerusalem) will descend out of heaven and will settle on the New Earth. The city will be in a cube 1,500 miles high, wide, and deep. It's slightly smaller than the moon and could accommodate 100 billion people.
Rev. 21:24 says, "And the nations shall walk by its light, and the kings of the earth shall bring their glory into it." The city will be so bright that it will illuminate the entire earth. Just like there are nations and kings on the present earth, so there will be on the New Earth. The "kings" of the earth are the people who were the most faithful servants of God in this present life. In the next life, those servants of God will be elevated to the highest positions. The kings of the earth will "bring their glory" into the New Jerusalem. Apparently the "glory" is something that's being produced on the New Earth, and the kings will have the privilege of bringing it into the city as an offering to honor the Lord.
Rev. 22:3 says, "The throne of God and of the Lamb shall be in it (the heavenly city), and His bondservants will serve Him." In the next life we will have job assignments that will be like eternal hobbies. We don't know what these jobs will be because it's beyond our present knowledge, but the best assignments will be granted to those who were the most faithful on the present earth. After we die and stand face-to-face with God, our knowledge will be expanded and then we will understand (1 Cor. 13:12). To hear the entire message on eternity, go to http://www.churchoflivingwater.net/node/23 and click on End Times pt. 8--"Eternity"