Luther's universal priesthood is, in part, a political doctrine that constitutes a revolutionary strain in Luther's thinking—a strain that can only be described as radical. Luther's political understanding of the universal priesthood posed a challenge to the concrete structures of his day, which were built upon a cosmological foundation that came under attack as a result of the Protestant Reformation. Thus, Luther's universal priesthood was not simply another evangelical concept that dealt with the office of ministry. It also served as the means for reordering the concept of temporal authority and the temporal order. Understood in this way, the universal priesthood had a political dimension that must be acknowledged if it is to be fully understood.