This is the first full day of the Easter triduum, a day commemorating the passion, crucifixion and death of Jesus Christ. Therefore, it is a day of strict fasting. The liturgy is profoundly austere, perhaps the most simple and stark liturgy of the entire year.
The liturgy of the Lord's passion consists of three parts: the liturgy of the Word, the veneration of the cross and the reception of Communion. Although Communion is given and received, this liturgy is not a Mass. The body of Christ that is received by the faithful on Good Friday was consecrated the prior evening at the Mass of the Lord's Supper and, in most cases, was adored until midnight or another late hour; this practice dates back to the earliest years of the Church and is meant to emphasize the somber, mournful character of the day.
The liturgy of the Word begins with silence. After a prayer, there are readings from Isaiah 52 (about the suffering Servant), Psalm 31 (a great Messianic psalm) and the epistle to the Hebrews (about Christ the new and eternal high priest). Each of these readings draws out the mystery of the suffering Messiah who conquers through death and who is revealed through what seemingly destroys Him.
Then the passion from the Gospel of John is proclaimed, often by several different lectors reading respective parts (Jesus, the guards, Peter, Caiaphas the high priest, Pilate, the soldiers).
In this reading the great drama of the passion unfolds, with Jew and Gentile, male and female and the powerful and the weak all revealed for who they are and how their choices to follow or deny Christ will affect their lives and the lives of others.
The simple, direct form of the Good Friday liturgy and readings brings the faithful face to face with the cross, the great scandal and paradox of Christianity. The cross is solemnly venerated after intercessory prayers are offered for the world and for all people. The deacon (or another minister) brings out the veiled cross in procession. The priest takes the cross, stands with it in front of the altar and faces the people, then uncovers the upper part of the cross, the right arm of the cross and then the entire cross. As he unveils each part, he sings, "This is the wood of the cross."
He places the cross and then venerates it; other clergy, lay ministers and the faithful then approach and venerate the cross by touching or kissing it. In this way each person acknowledges the instrument of Christ's death and publicly demonstrates their willingness to take up their cross and follow Christ, regardless of what trials and sufferings it might involve.
Afterward, the faithful receive Communion and then depart silently.
In the Byzantine rite, Communion is not even offered on this day. At vespers a "shroud" bearing a painting of the lifeless Christ is carried in a burial procession, and the faithful keep vigil before it through the night.
By venerating the cross, parishioners acknowledge the instrument of Christ's death and publicly demonstrate their willingness to take up their cross and follow Christ.