This book proposes that Christian worship is a key source for any theology seeking to understand the covenant between God and human beings in the Christian tradition. Through a detailed examination of phenomenological, biblical, and theologicalsources, the author seeks to write a theology in which the selfhood of God and human beings is seen as essentially vowed or covenantal . This claim is then explored through a detailed examination of eucharistic and baptismal practices within the worship life of the church. Here, then, is a theology that understands Christian worship as mutual acts of promise and commitment between God and human beings.