Ut Unum Sint §65

⁶⁵ Common roots and similar, if distinct, considerations have guided the development in the West of the Catholic Church and of the Churches and Communities which have their origins in the Reformation. Consequently these share the fact that they are "Western" in character. Their "diversities", although significant as has been pointed out, do not therefore preclude mutual interaction and complementarity. The ecumenical movement really began within the Churches and Ecclesial Communities of the Reform. At about the same time, in January, 1920, the Ecumenical Patriarchate expressed the hope that some kind of cooperation among the Christian Communions could be organized. This fact shows that the weight of cultural background is not the decisive factor. What is essential is the question of faith. The prayer of Christ, our one Lord, Redeemer and Master, speaks to everyone in the same way, both in the East and in the West. That prayer becomes an imperative to leave behind our divisions in order to seek and re-establish unity, as a result also of the bitter experiences of division itself.