The Sunday of the Holy Cross is the Third Sunday of Great Lent, also called Sunday of the Veneration of the Cross. On this Sunday, services includes a special veneration of the Cross, which prepares the faithful for the commemoration of the Crucifixion during Holy Week and the holy Resurrection.
Each of the Sundays of Great Lent has its own special theme. This Sunday’s theme is that in the cross of Christ crucified lies both “the power of God and the wisdom of God” for those being saved (1 Cor 1:24). On this Sunday in the middle of the Lenten season, the cross stands in the middle of the church, not merely to remind the faithful of Christ’s redemption and for them to keep the goal of their Lenten efforts, but also as a reminder: “He who does not take up his cross and follow me is not worthy of me” (Mt 10:38).
The historical theme, as seen in the hymnology, is the victory and joy of the cross, not the suffering. The Church fathers equate the life-giving cross with the tree of life and plant it in the middle of the Lenten pilgrimage. It was the tree that was planted in Paradise; it is to remind the faithful of both Adam’s bliss and how he was deprived from it.
For the catechumens of the early church, and the faithful preparing for Pascha today, the spiritual theme starts to change from personal faith, and personal effort, to Christ. The Church teaches that it is Christ’s cross that saves. One cannot take up his own cross and follow Christ unless one has Christ’s cross which he took up to save mankind. Partaking of this tree, one will no longer die, but will be kept alive.
This is done to refresh, reassure and to encourage those participating in Great Lent. The Church equates the appearance of the cross at this time to the banners and symbols that precede the return of a victorious king. The Epistle reading is from Hebrews 4:14-5:6 and explains Christ’s priesthood, and the Gospel lesson from Mark 8:34-9:1 ends with And He said to them, “Assuredly, I say to you that there are some standing here who will not taste death till they see the kingdom of God present with power.”
Before Thy Cross we bow down in worship, O Master, and Thy holy Resurrection we glorify. (Thrice)
Glory to the Father, and to the Son, and to the Holy Spirit, both now and ever, and unto the ages of ages. Amen.
And Thy holy Resurrection we glorify.
Before Thy Cross we bow down in worship, O Master, and Thy holy Resurrection we glorify.
Troparion (Tone 4) 
O Lord, save Your people,
And bless Your inheritance.
Grant victories to the Orthodox Christians,
over their adversaries.
And by virtue of Your Cross
Preserve Your habitation!
Kontakion (Tone 7) 
Now the flaming sword no longer guards the gates of Eden;
It has mysteriously been quenched by the wood of the Cross!
The sting of death and the victory of hell have been vanquished;
For You, O my Savior, have come and cried to those in hell:
“Enter again into paradise.”