The Dogmatic Constitution on the Sacred Liturgy of Vatican II reiterates the church's traditional teaching on the manifold presence of Christ in his church, especially in liturgical celebrations: in the priest, the consecrated bread and wine, the sacraments, and when the gathered church prays and sings. Nevertheless, there continues to exist in both scholarly writing and popular piety an almost exclusive focus on the presence of Christ in the eucharistic species. The purpose of this book is to examine the most elusive mode of the manifold presence of Christ mentioned above, that is, as it is symbolized within the assembly that gathers for worship. Using the resources of several contemporary philosophical aproaches, including semiotics, phenomenology, personalism, and existentialism, the book draws attention to the forgotten or or less understood aspects of the belief in the presence of Christ in the gathered assembly and explores the implications of this belief for participating in the liturgy and living the Christian life. While the book is scholarly in tone, it has extremely practical ramifications for the ways in which the mass should be celebrated in millions of Catholic parishes around the world.