"Finally! A renowned historian of liturgy explores at length the creative interplay between liturgical practice and theological reflection. This has been a desideratum for some time now, especially given the fresh readings of early Christian sources and the glimpses these provide of liturgical practices. In his new book, Max Johnson offers a nuanced, carefully argued, and expertly corroborated look at how doctrine shaped liturgical prayer and how prayer shaped the church's faith in the early centuries. Mapping the interplay between praying and believing in a multidimensional way, Johnson makes an important and much needed contribution to the ongoing conversation about the relationship between worship and doctrine in the church's life. I highly recommend this book."Teresa Berger, Yale Institute of Sacred Music, Yale Divinity School