“Belief in the Assumption of the Mother of God is clearly and unambiguously affirmed in the hymns sung by the Church on 14 August, the Feast of the ‘Dormition’ or ‘Falling Asleep’. But Orthodoxy, unlike Rome, has never proclaimed the Assumption as a dogma, nor would it ever wish to do so. The doctrines of the Trinity and the Incarnation have been proclaimed as dogmas, for they belong to the public preaching of the Church; but the glorification of Our Lady belongs to the Church’s inner Tradition:
It is hard to speak and not less hard to think about the mysteries which the Church keeps in the hidden depths of her inner consciousness…The Mother of God was never a theme of the public preaching of the Apostles; while Christ was preached on the housetops, and proclaimed for all to know in an initiatory teaching addressed to the whole world, the mystery of his Mother was revealed only to those who were within the Church. . .
…It is not so much an object of faith as a foundation of our hope, a fruit of faith, ripened in Tradition. Let us therefore keep silence, and let us not try to dogmatize about the supreme glory of the Mother of God. (V. Lossky)”
(Kallistos Ware, The Orthodox Church, p. 253)