During the reign of Constantine, first Roman Emperor to profess the Christian faith, his mother Helena went to Israel and there undertook to find the places especially significant to Christians. (She was helped in this by the fact that in their destructions around 135, the Romans had built pagan shrines over many of these sites.) Having located, close together, what she believed to be the sites of the Crucifixion and of the Burial (at locations that modern archaeologists think may be correct), she then had built over them the Church of the Holy Sepulchre, which was dedicated on 14 September 335. It has become a day for recognizing the Cross (in a festal atmosphere that would be inappropriate on Good Friday) as a symbol of triumph, as a sign of Christ‘s victory over death, and a reminder of His promise, “And when I am lifted up, I will draw all men unto me.” (John 12:32)
The Christian custom of tracing the sign of the cross on persons and things as a sign of blessing is very old. Some think that it goes back to the very origins of Christianity and earlier. In Ezekiel 9, we read that Ezekiel had a vision of the throne-room of God, in which an angel was sent to go through Jerusalem and put a mark on the foreheads of the faithful few who mourned for the sins of the city. Afterwards, other angels were sent through the city to destroy all those who had not the mark. We find similar visionary material in Revelation 7:2-4; 9:4; 14:1, where the mark on the forehead again protects the faithful few in the day of wrath, and it is said to be the name of the Lamb and of His Father.
What is the significance of the sign of the cross? Well, in the first place, we often place our initials or other personal mark on something to show that it belongs to us. The Cross is the personal mark of Our Lord Jesus Christ, and we mark it on ourselves as a sign that we belong to Him, just as in the book of Revelation, as noted above, the servants of God are sealed or marked on their foreheads as a sign that they are His.
James Kiefer