In Revelation 21:2 and 21:10 John “saw the holy city, New Jerusalem, coming down out of heaven from God.” This is the consummation of the promise in Revelation 3:12, “He who overcomes…I will write upon him the name of My God and the name of the city of My God, the New Jerusalem, which comes down out of heaven from My God.”
To prepare the way for New Jerusalem to come down, God came down in incarnation. Jesus told us that He is the Son of Man who came down out of heaven (John 3:13). In John 3 His coming down is to save us, give us eternal life, and make us His bride.
Furthermore, in John 6 Jesus told us that He is the bread that came down out of heaven that we may eat and live (v. 33, 50, 51, 58). He as the bread of life supplies us to live a heavenly life on earth. Everything of His first coming down prepares us to be the city of life, New Jerusalem, the bride of the Lamb.
Revelation 10:1-2 say, “I saw another strong Angel coming down out of heaven, clothed with a cloud; and the rainbow was upon His head, and His face was like the sun, and His feet like pillars of fire….And He placed His right foot on the sea and the left on the land.”
Christ’s placing His feet on the sea and on the land is His treading on them, and to tread on them is to take possession of them (Deut. 11:24; Josh. 1:3; Psa. 8:6-8). This indicates that Christ is coming down to take possession of the earth.*
Revelation 18:1 says, “I saw another Angel coming down out of heaven, having great authority; and the earth was illumined with His glory.”
In His second coming Christ takes possession of the earth and exercises His great authority to clear away the negative things, to prepare the way for New Jerusalem to come down out of heaven to earth.