See that you all follow the Bishop, as Christ does the Father, and the presbyterium as you would the apostles; and reverence the deacons, as a command of God. Let no one do anything connected with the Church without the Bishop. Let that be considered a valid Eucharist which is under the leadership of the Bishop, or one to whom he has entrusted it. Wherever the Bishop appears, there let the multitude of the people be; just as where Christ Jesus is, there is the Catholic Church
—St. Ignatius of Antioch, Letter to the Smyrneans 8 (c. 110 AD)