“‘Christian’ ecumenism relies on its support upon a vague but nonetheless real feeling of common Christianity which is shared by those who do not think or feel too deeply about the Church and its aims somehow to build a church comprising all such indifferent “Christians.” But common support can be dialogue with non-Christians rely on what possible ground can there be any kind of unity however loose between Christians and those who not merely do not know Christ but – as is the case with all the present-day representatives of non-Christian religions who are in contact with Christianity – decisively reject Christ?”
Fr. Seraphim Rose
~Orthodoxy and the Religion of the Future