An Explanation of the Sign of the Holy Cross
Student. Before we begin the first part of this doctrine, I would like you to propose to me what we are obliged to believe, starting with a simple explanation of the accompanying mysteries and also the matters contained in the creed that are more necessary in themselves.
Teacher. This is a good question. You ought to know that there are two principal mysteries of our faith contained in that which is called the sign of the Cross. The first mystery is the unity and the Trinity of God, while the second is the Incarnation and Passion of our Savior.
S. What do you mean by unity and Trinity?
T. These are sublime matters, and so they must be explained in the progress of this doctrine. But now it will be enough if you would take hold of, and understand these names. Unity of God is merely some matter transcending all created things; He did not have a beginning but always was and always will be; on the other hand, He preserves all other created things as well as rules them; this unity is the highest of all things, the most beautiful, the most noble, and the most powerful, the mistress of all things: it is called God, Who is One, accordingly it could only be one true Godhead, this is, only one nature and essence, infinite power, good wisdom, etc. Just the same, this Godhead is discovered in three persons, namely Father, Son, and Holy Spirit, threefold in regard to their persons but in regard to their nature and essence, which is the same, one. I will clarify the matter by an example. If three persons were merely on earth, of which one was Peter, another Paul, and the third, John, and they had one and the same soul and body, they would be said to be three persons because one would be of Peter, the other of Paul, and the third of John; just the same, it would be one man, not three, since neither have three souls nor three bodies, but one body and one soul. Clearly that is impossible among men, since their essence is meager and finite, therefore they cannot be in many persons. The essence of God, however, (since divinity is infinite) the same essence and the same divinity may be discovered in the Father, and in the Son, and in the Holy Spirit. Therefore they are three persons, for one is of the Father, one of the Son and one of the Holy Spirit, still God, although the Godhead has one will, one essence, one power, one wisdom, one goodness and so on and so forth.
S. Now tell me, what is the Incarnation and Passion of Christ our Savior?
T. This must be known; the second person in the Trinity, whom we name the Son, had a divine nature which He had before the creation of the world, nay more, from all eternity and He took up human flesh and a human soul; that is, He united our whole nature to Himself in the womb of the most chaste Virgin; He who had first been only God, thereafter began to be God and man. After He had lived with men for 33 years, had shown the way of salvation, performed many miracles and finally permitted Himself to be put on the cross and breathed His last to make satisfaction to the Father for the sins of the whole world; just the same he rose on the third day, and after the fortieth day after the Resurrection, He ascended into heaven. We will speak of this more in the explanation of the twelve articles of the Creed. And these things are what the Incarnation and Passion of our Savior mean.
S. Why is this particular matter a mystery of our faith?
T. Firstly, because it absolutely encompasses the beginning and the final end of man himself; secondly, because it offers the most unique and efficacious means to know this first beginning and end that must undeniably follow. Next, through faith and confession of these two mysteries we are set apart form the false sects of the heathen, such as Turks, Jews, and heretics. Next, because without faith and confession of these two mysteries no man can be saved.
S. In what arrangement are these mysteries understood in the most holy sing of the Cross?
T. When we make the most holy sign of the cross we say, “in the name of the Father, and of the Son, and of the Holy Spirit,” and we sign ourselves in the manner of the cross. We touch our forehead with our right hand while saying “In the name of the Father,” next the breast when saying, “of the Son,” and lastly, we raise our right hand, moving it from the left shoulder to the right while saying, “and of the Holy Spirit.” The phrase “in the name of,” signifies the unity of God, for we say, “in the name,” not names; likewise, it shows the Divine Power that is in the three persons alone. Next, the words, “of the Father and the Son and the Holy Spirit,” point out the persons of the Trinity. Moreover, the manner of signing oneself with a cross not only represents the Passion, but consequently also the Incarnation of the Son of God. The progression from the left to the right shoulder (but not from the right to the left), while using the right hand means we have been transported from transitory to eternal things, and from death to life.
S. For what reasons would we make the sign of the Cross?
T. First of all, we make it to call to witness that we are Christians, i.e. soldiers of Christ our General, and thus it is a specific symbol and becomes like a banner by which the soldiers of Christ are distinguished from the enemies of the Church, such as pagans, Jews, Turks, and Heretics. Secondly, we make this sign of the cross to invoke the Divine Assistance in all of our actions. For by this sign we invoke the most Holy Trinity through the merits of the passion of Christ our Savior. For this reason good Christians customarily make this sign when they rise from bed, or leave a house, or sit down for a meal, or leave the table, or when they undertake some business that must be made ready. Lastly, this sign is made so that we will be armed against diabolic temptations. The devil is certainly very scared of this sign, and he flees from it like criminals when they see the torture chamber. Therefore, by the sign of the cross a man is very often freedom from many dangers both spiritual and temporal, if he exercises the use of it with true faith and is equipped with confidence in the mercy of God and the merits of our Lord Jesus Christ.
The Catechism of St. Robert Bellarmine: Chapter I
– Lucas G. Westman