Book excerpt: The Reformation did not happen overnight, not with the singular act of posting of the Ninety-Five Theses, or even the presentation of the Augsburg Confession. Prof. Dr. Zeeden's classic study of how medieval church practices continued and developed within Lutheran church orders offers readers a unique perspective on how faith influences the act of worship. Historians of liturgy and theology will discover insights and important continuity between the Lutheran churches of the sixteenth century and their forebears of the late medieval period.