Ancient image of the Apostle Paul
(detail from fresco of Sts. Paul and Thecla),
the Grotto of Saint Paul, Ephesus, c. 500 A.D.
HOW TO MAKE THE SIGN OF THE CROSS
"In the name of the Father, ..."
Touch forehead with fingers of right hand — either with index and second finger side-by-side to signify the two natures in Christ, divine and human; or with thumb, index and second finger joined at the tips to signify the Holy Trinity
"and of the Son, ..."
Touch the lower chest or stomach
"and of the Holy ..."
Touch left shoulder (or right shoulder in the East)
"Spirit."
Cross over to right shoulder (or left shoulder in the East)
"Amen."
Fold hands together. ("Amen" comes from the Hebrew meaning "So be it.")
WHAT IS THE SIGN OF THE CROSS?
The sign of the cross is a sacramental, a sacred sign related to the sacraments that is a channel of God's grace. The Catechism of the Catholic Church states: "In Christ, Christians are blessed by God the Father 'with every spiritual blessing' (Eph. 1:3). This is why the Church imparts blessings by invoking the name of Jesus, usually while making the holy sign of the cross of Christ" (par. 1671).
WHY DO WE MAKE THE SIGN OF THE CROSS?
The sign of the cross is a way of blessing oneself with the sign of salvation. Imparting to one the graces earned by the shed blood of Our Savior Jesus Christ, it is a powerful sign of one's belonging to Christ (cf. Luke 9:23). The sign of the cross is a way of renewing one's Baptism (especially when used with holy water); and is reminder of the indwelling of the Blessed Trinity received in Baptism (cf. 1 Cor. 6:19).
The sign of the cross, like all of the Church's sacramentals (such as Scripture, holy water, holy oil, crucifixes, or the relics of saints) are patterned after the Incarnation, by which the invisible God became visible in Christ — "And the Word became flesh and dwelt among us" (John 1:14). Because Christ came to us in the flesh, sanctifying our humanity, now the body and bodily things, when consecrated to Him, can become sources of blessing.
Testifying to the power of the sign of the cross, Saint Athanasius, writing On the Incarnation of the Word in the fourth century, states, "[B]y the sign of the cross all magic is stopped, and all witchcraft brought to nought, and all the idols are being deserted and left, and every unruly pleasure is checked, and every one is looking up from earth to heaven ..." (31). The sacramentals of the Church are distinguished from superstition and magic. For while these things claim to operate by their own power or by demonic forces, giving glory to themselves or to the devil, sacramentals claim to work by the graces earned by Christ on the cross, giving glory to God. For this reason, the sign of the cross and other sacramentals, when used with faith, can be a way of protecting oneself when in the presence of evil. In fact, one of the proofs of a genuine demonic possession is an aversion to sacred objects.
THE SIGN OF THE CROSS IN SCRIPTURE & TRADITION
While there is not an explicit reference to the sign of the cross in the Bible, we do find a biblical precedent for it in the Book of Revelation, which speaks of the followers of Christ being set apart by a protective seal upon their foreheads (cf. 7:4, 9:4). The ancient Christian historical writings, moreover, tell us this sign dates back to the earliest days of the faith. Tertullian, for example, in about the year 200 A.D., writes, "At every forward step and movement, when coming in and going out, when putting on our clothes, when putting on our shoes, when bathing, when at table, when lighting the lamps, when reclining, when sitting, in all the ordinary occupations of our daily lives, we furrow our forehead with the sign" (The Crown 3:4).