The Roman Catholic, Orthodox, and Anglican Churches apply the term priesthood both to the ministry of bishops and presbyters and, more fundamentally, to the baptized members of those communions. Despite historical and theological differences among these churches, there are strong commonalities in the meaning and function of priesthood. To understand these commonalities and differences, it is necessary to consider the origins of Christian priesthood in its historical and religious contexts, major divergences, and continuing developments and controversies. Because it is the early centuries that these churches have in common, they require particular attention here.

The idea and practice of Christian priesthood in early Christianity formed around two poles: the nascent communities' understanding of themselves and of Jesus Christ in light of the Jewish traditions of priesthood with which he and they were familiar. Civic and religious priesthoods in the Greco-Roman world were also significant features of...