Matthew 24:14- And this gospel of the kingdom shall be preached in all the world for a witness unto all nations; and then shall the end come.
One gospel- singular:
Matthew 3:1, 2- In those days came John the Baptist, preaching in the wilderness of Judaea, And saying, Repent ye: for the kingdom of heaven is at hand.
Matthew 4:17- From that time Jesus began to preach, and to say, Repent: for the kingdom of heaven is at hand.
The kingdom of heaven on earth never stopped existing- only in the minds of hewn men. Let all the unbelievers ‘go to’ Moon and Mars…