David Dickson commenting on Psalm 47:9 shows that the visible Church can, should and will be one in its government throughout the world.
'As there is a necessity of the union of Jews and Gentiles in one visible Christian church, because it is promised and prophesied that it shall be so; so there is reason to wish for the more evident union of them, that they may be as eminently consociate as ever the Christian churches were, either in the Apostles' time, or in the Christian emperors' time, in a general assembly or oecumenical council; because there is at least a possibility of an oecumenical council, or a general assembly of Jews and Gentiles in this world under Christ their King. This place makes it plain, because after it is foretold that there shall be such a union of all the people of the God of Abraham, Jews and Gentiles, as their princes shall be gathered together, he takes away the chief ground of a great objection which may be made from the discord and disagreement of the princes of the world; some of them being averse altogether from the Christian religion, some of them from the true religion of Christ, and all of them almost dissenting one from another, and warring one against another; whereby now for many years the gathering of an cecumenical council hath not been possible. He meeteth this objection in the text, saying, for the shields of the earth belong unto God, that is, the hearts and power of all the kings of the earth are in the Lord's hand, and he hath the disposing of shields, armies, and ammunition, with all their commanders and rulers in the world, and therefore can make them serviceable for the nearest conjunction and union of his visible church, which can be for his glory in this world, as he sees fit, how and when he will.'
We need to recover the worldwide vision of the Second Reformation divines. Rutherford and Gillespie stressed on several occasions the ideal of an ecumenical Council of national churches. It is important to bear in mind the remarks of James Walker:
'The visible church, in the idea of the Scottish theologians, is catholic. You have not an indefinite number of Parochial, or Congregational, or National churches, constituting, as it were, so many ecclesiastical individualities, but one great spiritual republic, of which these various organizations form a part. The visible church is not a genus, so to speak, with so many species under it. It is thus you may think of the State, but the visible church is a totum integrale, it is an empire. The churches of the various nationalities constitute the provinces of this empire; and though they are so far independent of each other, yet they are so one, that membership in one is membership in all, and separation from one is separation from all . . . This conception of the church, of which, in at least some aspects, we have practically so much lost sight, had a firm hold of the Scottish theologians of the seventeenth century.' Dr. James Walker in The Theology of Theologians of Scotland. (Edinburgh: Rpt. Knox Press, 1982) Lecture iv. pp.95-6.