[Hermann the Cherusker]

And these were the only bishops in existence, right?

They were the only Bishops in existence throughout the Empire, and in Ethiopia, India, Persia, Armenia, Georgia, Scythia, etc. at the same time.

There were certainly little groups of heretics and schismatics like the Donatists here and there. None of them were part of a Church that stretched from one end of the earth to the other.

And many of these would have been men who held the doctrines of the Apostles, but saw no Scriptural warrant to organize in such a fashion.

Maybe they missed Acts 15.

[Free Baptist]

"Maybe they missed Acts 15."

There was one question to be answered by the Apostles in Jerusalem: whether the Gentile believers were bound by the Mosaic law regarding circumcision (a rite specific to the Jewish Nation).

And the conclusion was...

"...that we (the Apostles and the "certain men which came down from Judea - v. 1)) trouble not them, which from among the Gentiles are turned to God...that they abstain from the pollutions of idols, and from fornication, and from things strangled, and from blood." (vv. 19, 20) "to lay upon you NO GREATER BURDEN than these necessary things; that ye abstain from meats offered to idols, and from blood, and from things strangled, and from fornication: from which if ye keep yourselves, ye shall do well. Fare ye well." (vv. 28, 29)

"NO GREATER BURDEN."

So the Apostles passed on no system of administration. And the Jerusalem authority tends, through the history of the Book of Acts, to wane, as the Pauline authority continues through the remainder of the book, and NO GREATER BURDEN is ever added.

And through the Epistles, there is NO GREATER BURDEN in earthy religious things that have to do with any "Mother Church" in any place.