The office of bishop was already quite distinct from that of priest in the writings of Ignatius of Antioch (died c. 107), and by the middle of the second century all the chief centres of Christianity were headed by bishops, a form of organization that remained universal until the Protestant Reformation."bishop." Cross, F. L., ed. The Oxford Dictionary of the Christian Church. New York: Oxford University Press. 2005

Etymology

Bishop comes from the Greek word episkopos (ἐπίσκοπος, from ἐπί "over" and σκοπός "seeing") which can be translated overseer, superintendent, supervisor, the first, leader or foreman. From the word episkopos are derived the English words episcopacy, episcopate and episcopal. The system of church government by bishops is called episcopacy.

Bishops in the New Testament

The New Testament uses the word episkopos five times.

• Acts of the Apostles
• Epistle to the Philippians
• First Epistle to Timothy 3:2
• Epistle to Titus
• First Epistle of Peter 2:25

Words related to episkopos are used in two other verses. Some English Bibles transliterate this word as bishop (KJV, RSV, NRSV, etc.), while others use a more basic translation such as "overseer" (NIV, ESV, etc.). Biblical scholars differ on which, if any, of these verses refer specifically to ordained bishops as we understand them, and which simply refer to a generic "overseer" capacity.

The ministry of these New Testament episkopoi, according to some writers, was not explicitly commissioned by Jesus as far as the Gospels tell, but appears to be a natural, practical development of the church of the apostles during the first and second centuries AD. Others maintain that the episcopal structure of the Church was present from the beginning, being a direct institution by Jesus, referring to the apostles who clearly led the first local churches, governed and laid hands on the clergy and faithful.Fact: date=December 2008 Supporting this latter view, the portions of the New Testament that mention episkopoi do not appear to be ordering a new type of ministry, but giving instructions for an already existing position within the early Church.Fact: date=December 2008 In places (particularly in the verses from the Epistle to Titus) it appears that the position of episkopos is often similar or the same as that of presbyter (πρεσβυτερος), or elder and (or) priest. The Epistle to Timothy mentions deacons (διακονοι) in a manner that suggests that the office of deacon differs from the office of the bishop, and is subordinate to it, though it carries similar qualifications. Some references (e.g. Epistle to the Philippians ) indicate that a congregation might have multiple episkopoi, which is different than the bishop's role as it came to be established in the 2nd century.