In our previous post, we discovered where the Bible refers to the Catholic Church, through the "universal" mission that Christ gave to his apostles. Moreover, by the year 110 A.D., the term "Catholic" was already widely used by the first Christians. The title became formalized in order to draw distinction between the teaching of the Apostles, and the heretical and unorthodox teachings that were circulating and causing confusion among Christians. These heresies were inconsistent with the full deposit of faith transmitted by the Apostles. This is why, in part, Paul and others began writing letters to the Church, to clarify and spread the Good News of the Gospel.
"There is one God and one Christ, and one Church, and one chair founded on Peter by the word of the Lord. It is not possible to set up another altar or for there to be another priesthood besides that one altar and that one priesthood. Whoever has gathered elsewhere is scattering"
Cyprian, Letters 43:5 [A.D. 253]
"The consent of peoples and nations keeps me in the Church; so does her authority, inaugurated by miracles, nourished by hope, enlarged by love, established by age. The succession of priests keeps me beginning from the very seat of the apostle, Peter, to whom the Lord, after his Resurrection, gave it in charge to feed his sheep, down to the present episcopate. And so, lastly, does the name itself of Catholic, which, not without reason, amid so many heresies, the Church has retained; so that, though all heretics wish to be called Catholics, yet when a stranger asks where the Catholic Church meets, no heretic will venture to point to his own chapel or house."
St. Augustine of Hippo, Against the Letter of Mani Called 'The Foundation'" 4:5 [A.D. 397]