Forget Protester (in regards to our discussion), let’s start fresh.
How do you know that the CC is the one true church amongst all other Church’s?
From St. Optatus, writing against the Donatists and their schism:
calledtocommunion.com/2011/06/st-optatus-on-schism-and-the-bishop-of-rome/
I will let St. Optatus speak, writing against the Donatist schism…sometime in the AD300s…
calledtocommunion.com/201…ishop-of-rome/
St. Optatus’s Against the Donatists is composed of seven books (see the table of contents). After laying out the history of the schism in Book One, he turns in Book Two to the question: “Which is the One True Catholic Church and Where is it to be Found?” In what may be the most important and revealing statement in the whole of his work, he writes:
For it was not Caecilian who went forth from Majorinus, your father’s father,12 but it was Majorinus who deserted Caecilian; nor was it Caecilian who separated himself from the Chair of Peter, or from the Chair of Cyprian — but Majorinus, on whose Chair you sit — a Chair which had no existence before Majorinus himself.13
How does St. Optatus show that the Catholic Church did not go out from the Donatists, but that the Donatists went out from the Catholic Church? He does so by way of the Chair of St. Peter. The bishop that remains in communion with the Chair of St. Peter in Rome is the bishop who has remained with the Catholic Church. In this particular case, the bishop of Carthage who had remained in communion with the bishop of Rome, was Caecilian and his episcopal successors in Carthage. The bishop who has broken communion with the Chair of St. Peter is the bishop who is in schism from the Catholic Church. Therefore the bishop in Carthage who had broken fellowship with the Chair of St. Peter in Rome, was the bishop in schism from the Catholic Church. In this way St. Optatus shows that because Majorinus and his episcopal successors (and all the laypeople who followed them) had broken fellowship with the Chair of St. Peter, therefore they were the ones who had gone out from the Catholic Church, and were presently in schism from the Church.
Later in the work he shows that St. Peter, the Head of the Apostles, was the first to occupy the Episcopal Cathedra in Rome, and that the purpose of this Cathedra was to preserve unity among all Christians, including even the other Apostles. He writes:
You cannot then deny that you do know that upon Peter first in the City of Rome was bestowed the Episcopal Cathedra, on which sat Peter, the Head of all the Apostles … that, in this one Cathedra, unity should be preserved by all [in qua unica Cathedra unitas ab omnibus servaretur], lest the other Apostles might claim each for himself separate Cathedras, so that he who should set up a second Cathedra against the unique Cathedra would already be a schismatic and a sinner. Well then, on the one Cathedra, which is the first of the Endowments, Peter was the first to sit.25