Polycarp, disciple of the Apostle John, referring to the Church of God well into the first century. See the first line.
Another example The first epistle of Clement to the Corinthians...2nd line.
There are many other examples of the Early Church Fathers writing "To The Church of God, from the Church of God," etc.etc.
Oh, I know. My point was that the word "catholic" shows up in the writings of The Church just about as early as one can get.
Post #103 should say "well into the 2nd century"...with regards to Polycarp.