If both the immaculate birth of St. Mary and the Assumption of her body are not biblically documented, why does our Church, unlike the Catholic Church, believe in the second and reject the first?
There is a great difference between the Assumption of St. Maryís body, which we believe according to tradition, and the so-called immaculate birth of St. Mary, which is easily refuted from the Holy Scriptures.
The assumption of the body of St. Mary:
The belief in the assumption of the Holy Theotokos is ancient, dating back to the apostles themselves. What was clear from the beginning was that there were no relics of Maryís to be venerated, and that an empty tomb stood on the edge of Jerusalem near the site of her death. That location also soon became a place of pilgrimage. The Immaculate Conception:
At the Council of Chalcedon in 451, when bishops from throughout the Mediterranean world gathered in Constantinople, Emperor Marcian asked the Patriarch of Jerusalem to bring St. Maryís relics to Constantinople to be enshrined in the capitol. The patriarch explained to the emperor that there were none in Jerusalem and that "Mary had died in the presence of the apostles; but her tomb, when opened later was found empty."
We know from tradition how St. Thomas was absent at the time of St. Mary's departure and that on his way back to Jerusalem he saw angels carrying St. Mary's pure body and ascending to heaven. When he arrived at the disciplesí, after St. Mary's burial, he insisted on having seen the body; and when the disciples took him to the tomb to uncover the body they did not find it.
St. Thomas told them about his vision; so they prayed and the Lord promised them that they would see her in flesh another time. On the 16th day of Mesori the promise was fulfilled when they saw her at the right hand of her Son and her Lord, surrounded by the angelic Host as David prophesied saying "At Your right hand stands the queen" (Ps 45:9).
In the eighth century, St. John Damascene, known for his sermons at the holy places in Jerusalem, stood at the Tomb of Mary, and expressed the Church's belief in the meaning of the feast saying : "Although the body was properly buried, it did not remain in the state of death, neither was it dissolved by decay . . . You were transferred to your heavenly home, O Lady, Queen and Mother of God in truth."
It was on November 1, 1950, that Pope Pius XII declared infallibly that the Assumption of the Blessed Virgin Mary was a dogma of the Catholic Faith.
Likewise, the Second Vatican Council taught in the Dogmatic Constitution Lumen Gentium "the Immaculate Virgin, preserved free from all stain of original sin, was taken up body and soul into heavenly glory, when her earthly life was over, and exalted by the Lord as Queen over all things."
This concept is totally rejected by all the Orthodox churches because it is clearly against the teaching of the Holy Bible. Immaculate Conception means that St. Mary was born without the original sin. This in itself demolishes the whole basis of Christianity; for we believe that since Adamís fall, everyone is born carrying that original sin, "For all have sinned, and come short of the glory of God" (Romans 3:23). We do not distinguish St. Mary from the rest of the human race based on the assumption that she was born without the original sin. Her birth is like the birth of any common person. She herself said, "My soul magnifies the Lord, and my spirit has rejoiced in God my Savior" (Luke 1:46). If she was born without the original sin, then she would not need salvation. If so, why is she calling God her Savior?