The idea of koinonia has gained prominence in recent ecumenical discussions. Sr. Lorelei Fuchs here proposes koinonia, loosely translated as "communion," as the key to moving the fractured churches toward a future unity. Fuchs challenges churches to go beyond mere dialogue to apply their ecumenical insights at the local level. She begins by relating the exegetical meaning of koinonia to its ecumenical meaning, tracing the place of koinonia both within the churches and between the churches. Fuchs then examines koinonia in the extensive and fruitful dialogues that have taken place between Lutherans, Anglicans, and Roman Catholics, finally articulating a "symbolic competence for communionality" that provides a rich and workable way forward for church unity at all levels. Encompassing the latest in ecumenical thought, "Koinonia and the Quest for an Ecumenical Ecclesiology" provides a framework for moving closer to the reality of Christ's prayer "that all may be one."