From an interview with Metropolitan Hierotheos of Nafpaktos:
Question: The question of the participation of the Orthodox Church in what is called “ecumenical dialogue” with heterodox confessions raises great unease and disagreements inside the Church community. Between the overenthusiastic immersion in such rapprochement with the heterodox, which bleaches in a sense the boundaries dividing the Church and the world, and the often too easy scandalization by every move unjustifiably suspected of even slightly compromising the identity of the Orthodox Church as Una Sancta, which had led occasionally to schism, what is the right course that should be taken in dealing with this issue? Do you consider that such “ecumenical dialogue” could be of any use to the Church?
Answer: The two temptations you mention are dominant in our days. Sometimes there is an ultra-optimism leading to secularism and doctrinal minimalism, while sometimes there is a reaction leading to fundamentalism-fanaticism.
The point is not dialogue per se. The Apostles and the Fathers engaged in dialogue. The problem is a dialogue which alters theology as revelation of truth, and the Church as the unique Body of Christ, and pastoral care as the practice of the Church which leads to deification. The problem of the so-called Ecumenism lies on these points. The Orthodox Church is Ecumenical, that is, catholic-orthodox, because it possesses the wholeness of theology and the wholeness of life, but cannot be ecumenistic, that is, live a doctrinal minimalism and an ecclesiological aberration.
The fundamental point is that in such a dialogue between the Orthodox Church and other Denominations one must set an Orthodox ecclesiological basis and the participants must be people who live empirically the truth of the Church and have a patristic mind and view the doctrines in an inner way, not externally and conceptually. This means that they will see how the doctrine answers man’s existential problems, namely, what life is, what man is, and how man is united with God.
This is why in the Divine Liturgy we refer to the unity of faith and the communion of the Holy Spirit and not to the “union of the Churches” and the communion of firms, organizations, even “Christian” ones, nor to public relations actions.
From Sobornost, September 2006.