Between 1993 and 1996 a World Council of Churches study examined the relationship between ecclesiology -- our understanding of what the church is -- and ethics -- what the church does -- in responding to problems and issues facing the world today. Gathered in this single volume are the reports from three consultations (Costly Unity, Costly Commitment and Costly Obedience), along with major papers from the third, which focused on the church as a community in which people are formed morally. This ecumenical enquiry offers fresh insights into critical issues for all who are seeking a renewed vision of the ecumenical movement. Among the themes are: the imperative for ecumenical ethical reflection and engagement; the church as a community in which moral formation takes place -- through its teaching and through its life; the ethical dimension of worship, baptism and eucharist; the relation between koinonia (fellowship) and the quest for justice, peace and the integrity of creation; the churches' relationship to movements and action groups.