The Lord will be king over the whole earth. On that day there will be one Lord, and his name the only name.-Zechariah 14:9
God here is showing Zechariah something of great importance. If you read the rest of chapter 14, which is the last chapter in the book of Zechariah, you will see that this entire chapter is dedicated to telling us one thing and one thing only and that is that one day God will come and he will establish once and for all his kingdom here on earth. For you see the devil and his minions will only have control over the earth for a short period of time. And when the devil’s time of control and authority are over God is going to return and make this broken and dying world perfect again. He is going to return the earth to what is was like before the fall. John, the writer of the book of Revelation, describes what this will look like in two passages at the very end of his great vision. And the first one says this:
Then I saw “a new heaven and a new earth”, for the first heaven and the first earth had passed away, and there was no longer any sea. I saw the Holy City, the new Jerusalem, coming down out of heaven from God, prepared as a bride beautifully dressed for her husband. And I heard a loud voice from the throne saying, “Look! God’s dwelling place is now among the people, and he will dwell with them. They will be his people, and God himself will be with them and be their God. He will wipe every tear from their eyes. There will be no more death or mourning or crying or pain, for the old order of things has passed away.” He who was seated on the throne said, “I am making everything new!”-Revelation 21:1-5 NIV
And the second passage says this:
Then the angels showed me the river of the water of life, as clear as crystal, flowing from the throne of God and of the Lamb down the middle of the great street of the city. On each side of the river stood the tree of life, bearing twelve crops of fruit, yielding its fruit every month. And the leaves of the tree are for the healing of the nations. No longer will there be any curse. The throne of God and of the Lamb will be in the city, and his servants will serve him. They will see his face, and his name will be on their foreheads. There will be no more night. They will not need the light of a lamp or the light of the sun, for the Lord God will give them light. And they will reign for ever and ever.-Revelation 22:1-5 NIV
We must remember that one day God will make all things new and that one day he will establish his throne over the earth once and for all. We may not see it happen in our lifetime, but it will happen and we need to live our lives in such a way that reflects our faith that it will happen.