In the Lord's Prayer, we have the statement clearly made that the Kingdom will come, and then God's will shall be done in the earth. Obviously, as we look around us today, and in fact in any time during the earth's history since the Garden of Eden, this has not been the case. Great and significant changes must be made, and will be made, by God that Jesus' prayer may be fulfilled.
The promises, to which we have already referred, necessitate this. The promise made to Abraham was that he would inherit the land. The promise was that in him all nations of the earth shall be blessed.
In the book of Daniel, chapter 2, God showed Daniel (through a dream had by King Nebuchadnezzar of Babylon) exactly what was in store for the earth. This dream, given over 2,500 years ago has perfectly described the world's history.
The King saw a great statute in his dream. It had a head of gold, breasts of silver, thighs of brass, legs of Iron, and ten toes, partly iron, and partly clay.
Daniel explained to the king that he, Nebuchadnezzar, was the head of gold, in that this golden head represented the first world empire - the Babylonian empire. After him would come another empire, the silver, represented by Darius the Persian, and Medo-Persian empire. This would be followed by a third, which was Alexander the Great and Greek empire. The final empire would be the Roman empire, represented by the two legs of Iron.
After the Roman Empire, there would never be another world empire. All that would exist would be many nations, some strong, represented by the iron; and some weak, represented by the clay. As clay and iron cannot mix together, these nations would never be bound together to form another empire. And while Napoleon, Hitler, and others have tried, no one has ever been successful as the image prophesied.
Jesus is "the stone cut out of the mountain without hands." He smashes this image on its feet, the image crumbles, and in its place rises a great mountain, the Kingdom of God. It shall stand for ever. Here is God's intention for the earth. All the kingdoms of men, that God has permitted to exist for 6000 years, will be conquered by Christ with his saints near the end of those 6000 years. Therefore Christadelphians believe:
XIX.--That God will set up a Kingdom in the earth, which will overthrow all others, and change them into "the kingdoms of our Lord and His Christ."
And again:
XX.--That for this purpose God will send Jesus Christ personally to the earth at the close of the times of the Gentiles.
After walking with Jesus for 40 days following his resurrection, and after having listened to him explain God's plan of salvation for the world, this was their question. They didn't enquire about "kingdoms in heaven". Jesus answered that it was not for them to know the time. We still do not. But we know the time is approaching. Therefore Christadelphians teach:
XXI.--That the Kingdom which he will establish will be the Kingdom of Israel restored, in the territory it formerly occupied, namely, the land bequeathed for an everlasting possession to Abraham and his Seed (the Christ) by covenant.