ne of the defining symbols of the ancient church is the practice of making the “sign of the cross”. There are several ways in which this is done. The most popular is by making the sign with our hand to our forehead then to our chest, and then to each shoulder. This is done while speaking the phrase, “In the name of the Father, and of the Son and of the Holy Spirit”, or the Latin: “In nomine Patris et Filii et Spiritus Sancti”. Then clasp our hands back together saying “amen” which is the same in Latin.
The priest or bishop may make a similar gesture as a blessing toward an object or the congregation during certain rituals or during the liturgy. This “signum crucis” can be done with the same words or silently, but with the hand extended and opened flat while positioned vertically.
Another form is making a small cross shape with the thumb, which is most commonly done at the reading of the gospel in the Liturgy, where we make the sign on our foreheads, mouth and heart. Be in my mind, my words and in my heart.
The sign is also done during baptisms with the anointing with oil, on Ash Wednesday when ashes are placed on the forehead and other various devotions and rites. The mass begins and ends with the Signum Crucis, as well as novena’s, daily prayers and even prayers at meals.
The signum crucis was clearly in use by the third century in some form:
“In all our travels and movements, in all our coming in and going out, in putting on our shoes, at the bath, at the table, in lighting our candles, in lying down, in sitting down, whatever employment occupies us, we mark our foreheads with the sign of the cross” (De corona, 30). Tertullian (d. ca. 250)
And developed into other variations:
“Let us then not be ashamed to confess the Crucified. Be the cross our seal, made with boldness by our fingers on our brow and in everything; over the bread we eat and the cups we drink, in our comings and in our goings out; before our sleep, when we lie down and when we awake; when we are traveling, and when we are at rest” (Catecheses, 13) .St. Cyril of Jerusalem (d. 386)
Later more formal versions would develop that would be used during liturgy and for prayers and these have become a part of our identity as the church. The invocation and the action bring to mind the Most Holy Trinity to the believer in a “personal” custom, like wearing a wedding ring. The sign is a small action with great meaning; a symbol of sacramental substance and unseen reality, a prayer to begin a prayer; a prayer to end a prayer.
“In nomine Patris et Filii et Spiritus Sancti”.