Orthodoxy and the problem of unity

This article brings together two texts presented by the Orthodox delegation at the New Delhi Conference (1961): a collective declaration and a lecture by Nikos Nissiotis, deputy director of the Ecumenical Institute of Bossey. The study develops an Orthodox theology of ecclesial unity through a twofold approach: ecclesiological and ecumenical. The central idea contrasts an "ecumenism in space," deemed insufficient because it is limited to existing denominations, with an "ecumenism in time" grounded in a return to the common apostolic tradition. Nissiotis then articulates the notion of unity in relation to Trinitarian life and the event of Pentecost, distinguishing testimony (_martyria_) from service (_diakonia_). The theological contribution lies in a dynamic and inclusive redefinition of the term "orthodoxy," conceived not as a confessional label but as a synonym for "catholic" and "apostolic," thereby opening an original path for ecumenical reflection.