The Orthodox Church honors the Virgin Mary as someone more venerable than the Cherubim and incomparably more glorious than the Seraphim, someone who is above all creatures. She sees in her the Mother of God, who intercedes with her Son on behalf of the whole human race, imploring Him unceasingly for that intention.
The sentiment of love and veneration toward the Mother of God is the soul and heart of Orthodox piety, which warms and vivifies the whole body. Orthodox Christianity is life in Christ the Son of God and the Virgin, since the love of Christ is inseparable from the love of the Mother of God.
The Orthodox Church invokes in one breath the most holy name of Jesus and the most sweet name of Mary (this is why on Marian icons Mary is represented with the Child Jesus in her arms). The one who doesn't venerate Mary doesn't know Christ either.
And a faith in Christ that doesn't include a devotion to the Mother of God is a different Christian faith than the Church's faith.
Serge Boulgakov, quoted in: Donadeo Maria, Russian Marian Icons, Editions Mediaspaul, Paris, 1990.