Typically I think of Vos as the granddaddy of modern Reformed Amillennialism. Many of his spiritual descendants are now representing the so-called Radical 2 Kingdoms theology, which denies any visible cultural difference between believer and non-believer in the non-ecclesiastical realms. While his Amillennialism is still likely impeccable, I recently discovered a section in Vos which would place him well outside the non-interventionist sub-school of Amillennialism that looms so large today. In The Kingdom of God and the Church, Vos sounds downright Kuyperian. Here are some examples:
Undoubtedly the kingship of God, as his recognized and applied supremacy, is intended to pervade and control the whole of human life in all its forms of existence. This the parable of the leaven plainly teaches. These various forms of human life have each their own sphere in which they work and embody themselves. There is a sphere of science, a sphere of art, a sphere of the family and of the state, a sphere of commerce and industry. Whenever one of these spheres comes under the controlling principle of the divine supremacy and glory, and this outwardly reveals itself, there we can truly say that the kingdom of God has become manifest.
pg. 87-88, P&R 1972 ed.
Even more strongly, Vos writes:
And what is true of the relation between church and state, may also be applied to the relation between the visible church and the various other branches into which the organic life of humanity divides itself. It is entirely in accordance to subsume these under the kingdom of God and to co-ordinate them with the visible church as true manifestations of this kingdom, in so far as the divine sovereignty and glory have become in them the controlling principle. But it must always be remembered that the latter can only happen, when all of these, no less than the visible church, stand in living contact with the forces of regeneration supernaturally introduced into the world by the Spirit of God. While it is proper to seperate between the visible church and such things as the Christian state, Christian art, Christian science, etc., these things, if they truly belong to the kingdom of God, grow up out of the regenerated life of the invisible church.
While Vos clearly wants to distinguish Christendom from the visible Church (as he should) , he does not shy away from the concept itself. Notice that at the beginning of his list is “the Christian state.” This is consistent with the old Two Kingdoms theology of the Reformers. It is not consistent with the new version today.