The Church, during the apostolic age, did not consist of isolated, independent congregations, but was one body, of which the separate churches were constituent members, each subject to all the rest, or to an authority which extended over all.
What has 'theology' ever said that is of the smallest use to anybody? When has 'theology' ever said anything that is demonstrably true and is not obvious? What makes you think that 'theology' is a subject at all?