In order that the Lord may unite Himself with anybody, it is necessary that that man should be perfectly free from the impurity of sin and be adorned with virtues, or that he should believe in the Lord Jesus Christ, Who took upon Himself the sins of the whole world; that he should acknowledge his sins, should sincerely condemn them, considering them foolish, and that he should ask with all his heart to be forgiven them, firmly intending not to sin again in future. It was in this manner that all the saints were united with the Lord and became holy.
Union with God is achieved either through a life of virtue or a life of repentance. The lives of the saints demonstrate that these are one and the same thing. As St. Sisoe of the Desert said on his deathbed, (to the astonishment of his fellow monks): “I have not yet begun to repent.” Given this, what are we to make of the Virgin Mary? In what way was she worthy to become the Mother of God the Word, and is such a life possible for us?
How holy therefore must be our Lady, the Mother of God, with Whom God the Word Himself, the Light everlasting, was most truly united: ” the true light, Which lighteneth every man that cometh into the world,”  whom “the Holy Ghost came upon,” and whom “the power of the Most High overshadowed”!  How holy and most holy must be our Lady, the Mother of the Lord, Who became the temple of God, not made with hands, and was entirely penetrated, in all Her thoughts, feelings, words, and deeds, by the Holy Ghost, and from Whose blood the Creator Himself made flesh for Himself? Truly She is most holy, firm, steadfast, immovable, unchangeable throughout all eternity in Her most high, divine holiness, for the all-perfect God, Who humanly became Her Son, made Her all-perfect by reason of Her most great humility, Her love of purity and the source of purity, God; Her entire renunciation of the world, and Her attachment with all Her thoughts to the heavenly kingdom, and especially by reason of the fact that She became His Mother, carried Him in Her womb, and afterwards in Her most-pure arms, nourished with Her most-pure milk, Him Who feeds all creatures, cared for Him, caressed Him, suffered and sorrowed for Him, shed tears for Him, lived Her whole life for Him, for Him alone was wholly absorbed in His Spirit and was one heart, one soul with Him, one holiness with Him! O highest unity of love and holiness of the most-pure Virgin Mary and Her Divine Son, the Lord Jesus Christ! Wonderful, too, are God’s saints by their entire love for the Lord, by the streams of blood and sweat they shed out of love for the Lord.
The Virgin Mary is one of us. She was not conceived immaculately, as the Latins falsely claim, for then Our Lord would not have been fully human either. In the words of Irenaeus of Lyons” “For that which He [i.e. Christ] has not assumed He has not healed; but that which is united to His Godhead is also saved.” If Mary was unique amongst humanity, then Jesus Christ partook of that uniqueness — in which case the efficacy of Christ’s saving work is called into question.
The Virgin Mary has been glorified in and by means of her humility. Of all of humanity, she was the first to “see Him as He is”. Therefore, when we honor the Virgin Mary, we honor the One who built for Himself a body of her flesh and blood, and became one of us. We honor the Virgin Mary for her renunciation of the world, and her total focus on her Son, Jesus Christ. The totality of focus on the Lord Jesus Christ, as shown in the life of the Virgin Mary, and indeed of all the saints, is not simply a curiosity, but a matter of life and death. Their example shows us the way to life everlasting. Thanks be to God.
Sergieff, Archpriest John Iliytch; St John of Kronstadt (2010-05-26). My Life in Christ, or Moments of Spiritual Serenity and Contemplation, of Reverent Feeling, of Earnest Self-Amendment, and of Peace in God (Kindle Locations 4453-4468). . Kindle Edition.