It is important that Christians not be closed off among themselves, but open, and precisely in relations with the Orthodox I see how personal relationships are fundamental. We are to a great extent united in all the fundamental matters of doctrine, but it seems very difficult to make progress through doctrine. But drawing nearer to each other in communion, in the common experience of the life of faith, is the way to recognize one another as children of God and disciples of Christ. And this is my experience of at least forty, almost fifty years: this common experience of discipleship, which we finally live in the same faith, in the same apostolic succession, with the same sacraments and therefore with the great tradition of prayer as well; this diversity and multiplicity of religious cultures, of cultures of faith, is a beautiful thing. Having this experience is fundamental, and it seems to me, perhaps, that the conviction of some, of a segment of the monks of Athos, against ecumenism, is due in part to the fact that this experience is missing in which one sees and feels that the other person also belongs to the same Christ, belongs to dthe same communion with Christ in the Eucharist. Sot this is of great importance: we must endure the separation that exists. Saint Paul says that schisms are necessary for a certain time, and the Lord knows why: to test us, to exercise us, to make us mature, to make us more humble. But at the same time, we are obliged to proceed toward unity, and moving toward unity is already a form of unity.
– Pope Benedict XVI (March 2, 2006)