Of all the liturgical rules pertaining to the Great Fast, one is of importance for the understanding of the peculiar Tradition of our Greek-Catholic Church. It is one that has not been universally followed after our union with the Western Catholic Church. It is now becoming much more widely accepted as our Church is more completely embracing our Sacred Tradition. That liturgical rule, simply stated, is that the Divine Eucharistic Liturgy is not to be celebrated on weekdays of the Fast. The ancient rules are clear: under no circumstances is the Divine Liturgy to be celebrated Monday through Friday, during the Great Fast, with one exception: the major Feast of the Annunciation (the feast that celebrates when Mary conceived Jesus at the proclamation of the Archangel Gabriel). Tradition prescribes a special evening service of Communion which has been consecrated on Sunday. It is called the Liturgy of the Presanctified Gifts. This Tradition is based on a fundamental liturgical principle: the incompatibility of the Eucharist with fasting. To truly understand this principle, however, we have to first consider the meaning of the Eucharist.
The Eucharist has always preserved its festal and joyful character. It is the first of all mysteries of Christ’s coming and being present among His followers. So, in a very real sense, it is always the celebration of His Resurrection and is, of course, proof of His Resurrection. We must remember the story of Jesus meeting His disciples on the way to the town of Emmaus. His disciples did not recognize Him except in the “breaking of bread”. When He joined them for dinner, He took bread and broke it and gave it to them. When He did that, they immediately recognized Him.
The Eucharist must be for us, as it was for these disciples, a joy and “burning of heart” knowing that He is with us. So, the celebration of the Divine, Eucharistic Liturgy is always a celebratory occasion (This is also one reasons why we completely end the Divine Liturgy and close the Royal Doors before we serve a Panahyda. The Requiem service is not to be seen as a part of the Liturgy).
Every time the Church celebrates the Eucharist, she is in heaven. One understands then why the Eucharist is incompatible with fasting, for fasting is the main expression of the Church as still in a state of pilgrimage – a state of still making her way to the Heavenly Kingdom. Remember that Christ said that the “sons of the Kingdom” cannot fast while the Bridegroom is with them”. So then why do we distribute Communion on fast days?