From the Greek episkopos (overseer), this denotes the system of church government in which a bishop possesses the chief ecclesiastical authority. The NT evidence appears inconclusive. Episkopos and presbuteros (presbyter) are used interchangeably (cf. Acts 20:17,28). The threefold order of bishop, priest, and deacon seems likely to have emerged in the second century. The subject has provoked wide divergence of opinion and bitter controversy.