A joint publication of the World Council of Churches (WCC) and the ACT Alliance, this study document aims to clarify the understanding of ecumenical diakonia (the care that Christians offer to their fellow humanity, modeled on Christ's compassion, example and teachings). It provides a common platform for acting and reflecting together for churches and ecumenical partners worldwide. This major publication outlines the theological components of diakonia and offers practical content for those engaged in the service of diakonia. The study document is intended to be used for formation and training in ecumenical diakonia, to strengthen the institutional capacity of those involved in diakonia, and to foster dialogue and cooperation between churches, ecumenical partners, ACT Alliance and the WCC.