Theologian Brian Flanagan addresses the ways in which both holiness and sinfulness condition the life of the pilgrim church. The book is rooted in a liturgical-theological explanation of how the church prays through its continuing need for repentance and purification, as well as its belief in its present and future participation in the life of the Holy One.

After reviewing some of the ways in which past theologians have tried to explain the coexistence of ecclesial holiness and sinfulness, Flanagan suggests that, even if we can have confidence that God will fully sanctify the church in the reign of God, our ecclesiology must always attend to both the sanctity we already experience in the church and the sinfulness that is part of our continuing journey.