The first part of this work describes the development of Reformed Worship from 1500-1542. The story begins with liturgical reforms of the Christian Humanists in Alsace, continues through the establishment of the first Protestant worship services in the Swiss cities of Zurich and Basel, joins with the currents of French evangelical thought flowing from Meaux, and finally reaches Geneva with the publication of Calvin's first psalter. Reformed worship is presented as the fruit of an inner-church liturgical renewal movement begun well before the Reformation which was then cultivated by the Rhineland Protestant Reformers. In order that we might be clear about how patristic literature affected this process, we turn next to discover what the Reformers knew about the church fathers. We show evidence of the impressive patristic knowledge of such men as Zwingli, Brucer, Hedio, Oecolampadius, and Calvin. An extensive bibliography of patristic editions known and used by the Reformers concludes the second part of the book. Finally we analyze each element of Reformed worship to show its development and to indicate its scriptural and particularly its patristic roots. The Prayer of Confession, the Prayer of Intercession, the Communion Invocation, and the Benediction are studied to show their liturgical purpose. How the Reformers understood their use of the lectionary, the sermon, psalmody, and hymnody is presented in the light of their understanding of the practice of the ancient church.