"An apostolic church is more readily identifiable by being in spiritual unity with the apostles than in temporal descent from the apostles."
Until the advent of Protestantism, the ONLY bishops recognized as being apostolic were those who could trace their ordinal lineage back to the apostles. The Church took, and takes, great care to maintain the lists (the diptyches) of apostolic succession. The concept of "spiritual unity" with the apostles is distinctly Protestant and, by comparison, quite new.
For Orthodox Christians, the definition of The Church set out by +Ignatius of Antioch is the correct one. I am unaware of any Protestant group which fits that definition, though I understand the Anglicans might be able to make the claim. It is for that reason that +BXVI could write that Portestant churches are strictly speaking churches but rather ecclesial assemblies. From an Orthodox perspective, however, that does not of necessity mean that the potential for theosis is missing in Protestants.
You probably know that to an evangelical heart, that has a nice ring to it.
I think the early protestants did not concern themselves with ordinal lineage because they already had it...whether one speaks of Luther, Calvin (Deacon), Knox, the Anglicans, and others.
Therefore, they thought it more significant to be spiritual children of the apostles....the circumcision of the heart.
My Methodist Church can trace an ordinal lineage, but it is not of moment if the spiritual lineage is out of whack.
Neither, it seems, does the matter so appear to BXVI.
Following Augustine, BVXI recognizes two meanings for the Body of Christ, one spiritual, the other institutional. One can be "outside" the institutional meaning (i.e., the Church of Rome), and still be "inside" the spiritual meaning.
Although, recalling the life of Augustine and his "battle" with the Donatists, BVXI seemingly believes that the Body of Christ can have only one Head, which he locates in Rome (as did Augustine in his day). But this is to lay emphasis on the institutional meaning. The main thing at the end of the day, however, is salvation in Jesus Christ (the spiritual meaning).
Thank you so much for sharing your reflections on this matter with us, Kolokotronis.
Theological labels simply do not matter to me at all; I immediately recognize my brothers and sisters in Christ with as much certainty as if we grew up together.