The priesthood of all believers is either the general Christian belief that all Christians form a common priesthood, or, alternatively, the specific Protestant belief that this universal priesthood precludes the ministerial priesthood (holy orders) found in some other churches, including Catholicism and Eastern Orthodoxy.
The inclusionary Catholic version proposes a common priesthood that is different from both Holy Orders and the priesthood of Christ. The exclusionary version, elaborated in the theology of Martin Luther, Henry VIII, Ulrich Zwingli and John Calvin, became prominent as a tenet of Protestant Christian doctrine, though the exact meaning of the belief and its implications vary widely among denominations.