 According to some interpreters, especially Philipp Jakob Spener, Luther developed the notion of all believers being "part of one body"
as a means to claim the priesthood of all believers.While the notion and meaning is somewhat unclear, this concept was clearly developed in opposition against a prevailing medieval division of Christians into "spiritual" (the hierarchy) and "temporal" Christians (the laity).In this view all Christians are "priests" in the eyes of God.