"By men [sic] assembling here and there in the Holy Spirit there arises here and there a visible Christian congregation. It is best not to apply the idea of invisibility to the Church; we are all inclined to slip away with that in the direction of a civitas platonica or some sort of Cloud-cuckooland, in which the Christians are united inwardly and invisibly, while the visible Church is devalued." - Karl Barth, Dogmatics in Outline. h/t Steve.Check out Andrew Errington's post on "Assembled in Heaven?".