God will not always be in the third heaven as when all things are finished here on earth after the return of Christ God will make new again this present heaven and earth then He will usher down the New Jerusalem (Spiritual Kingdom of God). God will then be with us as the tabernacle of God is with men and He will dwell with us and we with Him forever. For now the kingdom of God is within us as we are made kings and priest of God as we reign with Christ here on earth until the seventh trumpet sounds and then the nations (kingdoms) of this world become the nations (kingdoms) of God and of Christ and He will be our God and we His people forever.
The tabernacle of God within the New Jerusalem is not that which is made by hand as neither is the New Jerusalem. When we are given spiritual bodies (glorified bodies) then we will see all things of God that are spiritual for in our mortal bodies we can not even perceive what the New Jerusalem will look like just as we can not even know what Christ looks like, but know we will be just like Him in our glorified bodies.
Third Heaven - This is where God, Jesus and the holy angels dwell plus the very breath of just men dwell as when we die it is that breath that returns back to God. It is called The heaven of heavens, (Deuteronomy 10:14; 1 Kings 8:27; Psalms 115:16; 148:4). (1Kings 8:27) The heavens, even the highest heaven, cannot contain you. The third heaven is beyond the space and stars. Where no man has seen by telescope. This heaven is the dwelling-place of God (John 3:13).
Daniel 7:27 And the kingdom and dominion, and the greatness of the kingdom under the whole heaven, shall be given to the people of the saints of the most High, whose kingdom is an everlasting kingdom, and all dominions shall serve and obey him.
Luke 17:20 And when he was demanded of the Pharisees, when the kingdom of God should come, he answered them and said, The kingdom of God cometh not with observation: 21 Neither shall they say, Lo here! or, lo there! for, behold, the kingdom of God is within you.
Rev 3:10 Because thou hast kept the word of my patience, I also will keep thee from the hour of temptation, which shall come upon all the world, to try them that dwell upon the earth. 11 Behold, I come quickly: hold that fast which thou hast, that no man take thy crown. 12 Him that overcometh will I make a pillar in the temple of my God, and he shall go no more out: and I will write upon him the name of my God, and the name of the city of my God, which is new Jerusalem, which cometh down out of heaven from my God: and I will write upon him my new name. 13 He that hath an ear, let him hear what the Spirit saith unto the churches.
Rev 5:10 10 And hast made us unto our God kings and priests: and we shall reign on the earth. (We are the Spiritual Kingdom of God on earth)
Rev 11: 15 And the seventh angel sounded; and there were great voices in heaven, saying, The kingdoms of this world are become the kingdoms of our Lord, and of his Christ; and he shall reign for ever and ever. (We are that Spiritual kingdom of God while here on earth as we reign with Him over the nations)
Rev 21:1 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. 2 And I John saw the holy city, new Jerusalem, coming down from God out of heaven, prepared as a bride adorned for her husband. 3 And I heard a great voice out of heaven saying, Behold, the tabernacle of God is with men, and he will dwell with them, and they shall be his people, and God himself shall be with them, and be their God.
