During the last few decades there has been a debate concerning the prominence of ecclesiology in the Gospel of John. This book highlights that debate and makes an important contribution to our understanding of Johannine ecclesiology. It argues that ecclesiology is a major theological concern of the Gospel, that investigations into Johannine ecclesiology have suffered under categories that are alien to the Gospel itself, and that the Gospel espouses a christological ecclesiology that emphasizes the origin, nature and purpose of the community. The community is Christus prolongatus; Christology and ecclesiology overlap. In addition, the book makes several new suggestions: that the prayer of the Johannine Jesus in John 17 has its origin (Sitz im Leben) in the 'law-court' petitionary prayers of the Johannine community in its conflict with the synagogue; that the Johannine concept of glory has to be understood in soteriological terms and is closely related to the Johannine community's sense of mission; and that the Johannine concept of sending reflects a gnostic sending tradition that was current in first-century Palestine.