IT IS beyond any question that she who was chosen to be the Mother of God represents the summit of Old Testament holiness.
If St. John the Baptist is called “the greatest” of those before Christ, that is because the greatness of the All-Holy Mother of God belongs not only to the Old Testament, where she was hidden and does not appear, but also to the Church, in which she realized her fullness and became manifest, to be glorified by all generations (Luke 1:48).
The person of St. John remains in the Old Testament dispensation; the most holy Virgin passes from the Old to the New; and this transition, in the person of the Mother of God, shows us how the New Covenant is the fulfillment of the Old.
Vladimir Lossky, “Panagia”: Chapter 11 of “In the Image and Likeness of God” (St Vladimir’s Seminary Press: New York, 1974).
WHAT shall we call thee, O thou full of grace?
The heavens, for thou hast risen upon us the sun of righteousness.
Paradise, for thou hast nurtured the flower of incorruption.
Virgin, for thou hast remained incorrupt.
Pure mother, for thou hast held in thy holy embraces a son which is God of all.
Intercede with him, that he might save our souls.
At the Great Hours, said in the days leading up to Christmas. For many more poetic titles of the Blessed Virgin, see also O Virgin Pure (Ἀγνή Παρθένε) by St Nektarios of Aegina.