Someday, I believe, the New Jerusalem will come down to earth so as to bring its splendor and glory from God to all the earth. The full reign of the kingdom of God in Jesus will be known to all.
Now we live in a world of a different sphere. In a real sense there is nothing at all in common with the kingdom of God come in Jesus, the holy nation scattered now throughout the earth, and the kingdom of this world, made up of nations and peoples. This is not to say that God doesn't use the "kingdoms" of this world in his inscrutable but good ways. But that they are not at their heart part of the kingdom of God come in Jesus.
The New Jerusalem in Jesus, in its essence has already come, and it is subversively to be the means of change in the community of God in Jesus. We don't come in stealthily, but openly, with wisdom as Jesus did here on earth. Our message first must be seen in our lives together and individually, as a witness to the world. We must live out our calling in the reality of what we are as the Body of Christ in this world. This involves, from his heart, being his hands and feet, and speaking from him, the Word of God by the Spirit. All people need to see the love of God in Christ made manifest in Christ's Body on earth, as we love each other, our neighbors as ourselves and our enemies.
Political action such as in the case of William Wilberforce is good, and in that case was like a dynamo come down from heaven to earth to shake up and affect the world for good, according to God's will, in the abolition of slavery. Good can come from political action and we should participate in this sphere where we can for the good of our neighbor as well as for the cause of the gospel not to be hindered.
But we must also realize that when we participate in the political process now, we're part of a different sphere invading this good yet fallen world, in which much evil is at work. Ours in Jesus is the kingdom of God, the New Jerusalem, which is not going to make a treaty with Washington D.C. or any other nation, but has invaded to bless all, in Jesus, and someday will fully realize God's good reign of love to all.
Do you see this differently and how, and why? Or what might you add?