Consider: -The church both learns and becomes what it truly is when it gathers to worship. -Worship tells the story of God's salvation history and invites God's people into it. -By doing so, the church offers the world both a stern warning and a hopeful promise. These are three of the key insights that animated the work of Jean-Jacques von Allmen, a Swiss Reformed pastor and professor who is among the most admired liturgical theologians of the twentieth century. Yet his work is largely and lamentably unknown to most worship leaders. In this book, Ron Rienstra provides an introduction to this important thinker. He offers methodological and biographical context and then explores von Allmen's most generative insights concerning the church as it engages in its most foundational activity: worship. Viewed through the lens of the Nicene marks, Rienstra's exploration yields the outlines of a ""liturgical ecclesiology"": a way to help the church think more deeply about its identity and to help its leaders shape the worship they prepare and lead today. ""It is often difficult to move liturgical theology beyond the boundaries of definition and methodology and into more fruitful and pastorally relevant conversations. This book successfully navigates such a dynamic move with ease and accessibility. Rienstra's examination of liturgical ecclesiology through the life and work of Jean-Jacques von Allmen truly represents a new moment in this nascent field of inquiry and wonderfully captures the 'boots-on-the-ground ecclesiological experience' of the pastor, reformer, theologian, publisher, and ecumenist."" --Porter Taylor, University of Aberdeen ""Ronald Rienstra is an expert and winsome guide to von Allmen's writings. Those familiar with those writings will find their appreciation deepened by Rienstra's analysis, and the uninitiated will discover a rich new source for reflection and devotion. Rienstra's treatment is pervaded with the same kind of love for Christ, for worship, and for the church that infuses von Allmen's work itself."" --Ron Man, Director, Worship Resources International ""Jean-Jacques von Allmen is one of the leading theologians of liturgy in the Reformed/Presbyterian tradition in the twentieth century, whose books draw together insights from his many pastoral, historical, theological, and ecumenical encounters in often striking and generative ways. How wonderful it is to have a contemporary tour guide to this rich source. Thank to Ron Rienstra for his research on von Allmen's work, and his vision for strengthening the theological vision that guides our worship practices."" --John D. Witvliet, Calvin College and Calvin Theological Seminary ""It's almost criminal that a book like this only now sees the light of day. Von Allmen is, arguably, one of the best-kept secrets in the field of liturgical studies. But no more. Rienstra's treatment of this pastor-theologian's thoughts on worship deserve to be read by Christians across denominational lines. Pastor, teacher, worship leader: take up and read!"" --W. David O. Taylor, Fuller Theological Seminary Ronald Andrew Rienstra is Professor of Preaching and Worship Arts at Western Theological Seminary in Holland, Michigan. He is the author of Worship Words (2009) and many articles published in Reformed Worship.