The following is taken from the book "Meditations for Advent, Preparing for Christ's Birth" by Fr Vassilios Papavassiliou, published by Ancient Fath Publishing.
The Church teaches us the theology of the Scriptures not only with hymns, but also with images. Iconography is one of the "languages" into which Scripture is translated. Thus man of our icons also contain allusions and references to Old and New Testaments. Of particular interest is the icon of the Nativity.
The comparison between the birth and the burial of Christ is made very explicit in our iconography. If you look carefelly at almost any traditional Orthodox icon of the Nativity, you will notice that the crib in which the baby Jesus is laid is depicted as a tomb, and the swaddling clothes resemble a burial shroud.
We read in the Gospel (Matthew 27:57-60) that Joseph of Arimathea takes the body of the crucified Jesus and buries it in a "new tomb" - a tomb in which no one had been laid before. The Church makes a comparision between the virgin womb and the virgin tomb, between the cave in which Christ is born and the grave from which He rises again.
This comparison is made even more explicit in the service of the Royal Hours. At the Royal Hours on Great Friday morning, we chant this hymn of the Passion:
Today, He who hung the earth upon the waters is hung upon a tree.
At the Royal Hours on Christmas Eve, we chant a hymn that is identical in form and style to that of Great Friday:
Today, He who holds creation in the palm of His hand is born of a Virgin.
Why is there such similarity between these two apparently very different feasts - the one a joyful celebration of life, the other a sorrowful commemoratin of death? Because in both feasts the Church is inviting us to consider the same paradox. On Great Friday, the paradox is how can God, who is eternal - who has no end - be killed? On Christmas Eve, the paradox is how can God, who is eternal - who has no beginning - be born?
As one of the hymns of Christmas Vigil says:
How is He contained in a womb, whom nothing can contain?
God enetered the world in order to take on the fullness of human existance, which means not only the fullness of human life, but also the fullness of human death. He was made in our "image and likeness" in order to die like us and raise our humanity with Him to God the Father, to restore and complete in us His Image and Likeness in which we were made. Thus we cannot remember the Lord's birth without considering also His death and Resurrection. There would be no salvation for humanity without the Cross, but there would be no Cross without the Nativity. Jesus was born to die, and He died to save all.