I had the privilege of being back there in attendance only once in my life, and I have never forgotten it, the awe and splendor of the divine humiliation.
What a surprise to meet God, and to find out that He is not here to annihilate you, but to restore you.
The service of the proskomidí is what I learned to call it from the first Orthodox presbyter I ever knew, Father Ihor Kutash, a Ukrainian Greek Orthodox priest in Canada, just a few years older than me, when I witnessed my first Orthodox liturgy in a country church in the village of Bellis, Alberta. It is also called, less mystically, the office of oblation. The full text and explanation can be found here, at the Greek Archdiocese website, from which the following brief excerpt is taken.
Since the early Church, the Office of Oblation (Proskomide) has been a service of offering gifts to God in preparation for the Sacrament of Holy Eucharist or Holy Communion in the Divine Liturgy. The Office of Oblation is thus a prerequisite for the Divine Liturgy.
Today, the priest conducts the Office of Oblation inaudibly during Matins behind the Altar Iconostasis (Icon Screen). The Table of Oblation (Prothesis or sometimes Proskomide) is located to the left of the Holy Altar table. The Table of Oblation represents the cave or stable of Bethlehem where our Lord and Savior Jesus Christ was born.
For the Oblation, members of the congregation bring wine and bread as an offering to the Church. During the Divine Liturgy, the wine will be consecrated into the blood of Christ, while the bread will be consecrated into the body of Christ.
The wine is a pure grape sweet wine. It is often the Greek sweet wine Mavrodaphne or the sweet wines from Samos or Cyprus.
The holy bread (also called prosphora or offering) must be made from pure wheat flour and water, and is leavened and well baked. Usually, there are five loaves to represent our Lord's miracle of feeding of "five thousand men besides women and children" with only five loaves of bread (Matt. 14:17-21). But if it is not possible to make five loaves, at least one is necessary for the offering.
In the center of the top of the bread is a round seal. During the Office of Oblation, the priest cuts small portions of the bread to prepare for Holy Communion. The seal on the bread looks like this:
The full text of the service and the ceremony that goes with it, as well as an explanation of all the implements that are used and what they represent, can be read by clicking here. The same breads, prósphora (PROSS-for-ah) that are consecrated for the mystery of Holy Communion are also distributed after an ordinary blessing (not consecrated) to everyone who has been present at the divine liturgy. In this form, the chunks of bread are called antídoron (ahn-DEE-dho-ron), or in English, the ‘bread of fellowship’. You never come away from Orthodox worship without receiving something, even if it is a fragment of freshly baked bread.
‘O gracious image
embossed upon the several measured loaves,
secretly yeasted, and browned
within the earthen ovens of tribulation.’
— from the poem “O purified virgin” by Athanasius Blalock