Rev. Setri Nyomi, the general secretary of the World Alliance of Reformed Churches, protested the Vatican statement in a letter to Cardinal Walter Kasper, the president of the Pontifical Council for Christian Unity. Rev. Nyomi said that the new Vatican statement, which says that Protestant groups are not "churches" in the proper sense, "makes us question the seriousness with which the Roman Catholic Church takes its dialogues with Reformed family and other families of the Church."
The World Council of Churches (WCC) also expressed disagreement with the Vatican. In its own statement addressing the role of the Catholic Church, the WCC argued that the term "catholic" should be understood to mean "universal." In that sense, the WCC argued, "Each church is the Church catholic and not simply a part of it. Each church is the Church catholic, but not the whole of it."
The Russian Orthodox Church, however, welcomed the Vatican satement. "For an honest theological dialogue to happen, one should have a clear view of the position of the other side," said Metropolitan Kirill of Smolensk, the leading ecumenical official of the Moscow patriarchate.
Metropolitan Kirill observed that he saw "nothing new" doctrinally in the statement released on july 10 by the Congregation for the Doctrine of the Faith. He argued that "everything contained in the Catholic document rightfully applies to the Orthodox Church," since the Orthodox Church has preserved apostolic succession.
The Vatican document acknowledged that the Orthodox churches are sister churches with valid sacraments, but added that in the Orthodox world, "of the division between Christians, the fullness of universality, which is proper to the Church governed by the Successor of Peter and the bishops in communion with him, is not fully realized in history."