Question: "Making the sign of the cross became a practice in the 4th century. The apostles, Christ and nobody in the ancient Church practiced it, so why should we?"
This question is based on a false premise. The earliest reference to the practice of making the sign of the Cross comes from Tertullian (who lived between c. 160 – c. 225 AD):
"And how long shall we draw the saw to and fro through this line, when we have an ancient practice, which by anticipation has made for us the state, i.e., of the question? If no passage of Scripture has prescribed it, assuredly custom, which without doubt flowed from tradition, has confirmed it. For how can anything come into use, if it has not first been handed down? Even in pleading tradition, written authority, you say, must be demanded. Let us inquire, therefore, whether tradition, unless it be written, should not be admitted. Certainly we shall say that it ought not to be admitted, if no cases of other practices which, without any written instrument, we maintain on the ground of tradition alone, and the countenance thereafter of custom, affords us any precedent. To deal with this matter briefly, I shall begin with baptism. When we are going to enter the water, but a little before, in the presence of the congregation and under the hand of the president, we solemnly profess that we disown the devil, and his pomp, and his angels. Hereupon we are thrice immersed, making a somewhat ampler pledge than the Lord has appointed in the Gospel. Then when we are taken up (as new-born children), we taste first of all a mixture of milk and honey, and from that day we refrain from the daily bath for a whole week. We take also, in congregations before daybreak, and from the hand of none but the presidents, the sacrament of the Eucharist, which the Lord both commanded to be eaten at meal-times, and enjoined to be taken by all alike. As often as the anniversary comes round, we make offerings for the dead as birthday honours. We count fasting or kneeling in worship on the Lord’s day to be unlawful. We rejoice in the same privilege also from Easter to Whitsunday. We feel pained should any wine or bread, even though our own, be cast upon the ground. At every forward step and movement, at every going in and out, when we put on our clothes and shoes, when we bathe, when we sit at table, when we light the lamps, on couch, on seat, in all the ordinary actions of daily life, we trace upon the forehead the sign [of the Cross]" (De Corona, Chapter 3).
Tertullian was not trying to defend the traditions he mentioned in this passage. He was appealing to these unwritten traditions to defend a Christian soldier who had refused to wear a laurel wreath crown in a ceremony in which the soldiers were receiving a bonus from the Emperor, which sparked a local persecution of Christians. Tertullian's point was that this soldier was following the tradition of the Church, though many argued he should have gone along with the ceremony, and spared others the persecution that followed his refusal -- and one of their arguments was that there was nothing in Scripture that dictated this soldier's actions.
Tertullian appealed to these other traditions because they were uncontroversial, and ancient. This treatise was written in 201 AD, by a man born in 160 AD. Would such a man consider something to be an ancient tradition if it were less than a century old? I don't think so.
Even in our time, we pass along oral histories that go back at least 100 years, and Tertullian lived in a culture in which preserving oral history was a much bigger part of the culture, and change happened far more slowly. I was born in 1966, and my grandfather on my father's side was born in 1878. He died a year before I was born, but I was told a lot about him by my father. He was born in Iowa, but went to Texas as a young man, and for awhile he worked as a cowboy, before settling down and becoming a farmer. He lived to see the invention of the car, the airplane, radio, television, the atom bomb, and space flight. That is an incredible amount of change for one to see in a single lifetime. When my grandfather first heard about the invention of the radio, he thought someone was pulling his leg. "What do you mean? Sound flies through the air for miles, and then you hear it through an electric box?" This story of my grandfather's reaction to news of the invention of the radio is just about 100 old. There are a great many oral histories that I have heard that go back a hundred years or more. And anyone who listens to old people tell their stories will likewise hear a whole lot of oral history that covers the better part of a century.
If making the sign of the Cross was something that originated even 50 years before Tertullian made mention of the practice, there would have still been people alive in the Church who would have remembered its introduction, and it is unlikely that there would not still be some discussion of this change in piety as long such people were still around. So it stands to reason that the practice could not have originated very much after the end of the first century... if it did not originate well before then. After all, this would not have been a minor change in Christian piety, because as Tertullian says, the sign of the Cross is something we do "At every forward step and movement, at every going in and out, when we put on our clothes and shoes, when we bathe, when we sit at table, when we light the lamps, on couch, on seat, in all the ordinary actions of daily life."
One other argument in favor of the antiquity of making the sign of the Cross is the fact that it undoubtedly was the universal practice of the Church when Tertullian wrote this treatise. How would that have come about, if it was a relatively recent change? There is no record in the early Church of there ever having been a controversy about making the sign of the Cross.
The oldest record of the content of Christian catechisms is the catechetical lectures of St. Cyril of Jerusalem, and here is what he says about making the sign of the Cross:
"Let us, therefore, not be ashamed of the Cross of Christ; but though another hide it, do thou openly seal it upon thy forehead, that the devils may behold the royal sign and flee trembling far away. Make then this sign at eating and drinking, at sitting, at lying down, at rising up, at speaking, at walking: in a word, at every act (Catechetical Lectures 4:14).
St. Basil the Great made a very similar argument to Tertullian in his Treatise on the Holy Spirit (66-67), though he used it to defend the teaching that the Holy Spirit was a person. He made the argument that the ancient doxology "Glory to the Father, and to the Son, and to the Holy Spirit" was evidence that the Holy Spirit was a person, as are the Father and the Son. But in response to the argument that this doxology was not found in the Bible, but only in the liturgical tradition of the Church, he responded:
"Of the beliefs and practices whether generally accepted or publicly enjoined which are preserved in the Church some we possess derived from written teaching; others we have received delivered to us “in a mystery” by the tradition of the apostles; and both of these in relation to true religion have the same force. And these no one will gainsay;—no one, at all events, who is even moderately versed in the institutions of the Church. For were we to attempt to reject such customs as have no written authority, on the ground that the importance they possess is small, we should unintentionally injure the Gospel in its very vitals; or, rather, should make our public definition a mere phrase and nothing more. For instance, to take the first and most general example, who is thence who has taught us in writing to sign with the sign of the cross those who have trusted in the name of our Lord Jesus Christ? What writing has taught us to turn to the East at the prayer? Which of the saints has left us in writing the words of the invocation at the displaying of the bread of the Eucharist and the cup of blessing? For we are not, as is well known, content with what the apostle or the Gospel has recorded, but both in preface and conclusion we add other words as being of great importance to the validity of the ministry, and these we derive from unwritten teaching. Moreover we bless the water of baptism and the oil of the chrism, and besides this the catechumen who is being baptized. On what written authority do we do this? Is not our authority silent and mystical tradition? Nay, by what written word is the anointing of oil itself taught? And whence comes the custom of baptizing thrice? And as to the other customs of baptism from what Scripture do we derive the renunciation of Satan and his angels? Does not this come from that unpublished and secret teaching which our fathers guarded in a silence out of the reach of curious meddling and inquisitive investigation? Well had they learnt the lesson that the awful dignity of the mysteries is best preserved by silence. What the uninitiated are not even allowed to look at was hardly likely to be publicly paraded about in written documents"
And again, he was not defending the practice of making the sign of the Cross, he was appealing to it as a tradition that even the heretics would not deny.
Interestingly, Christians making the sign of the Cross played a role in the beginning of the last great persecution of the Church prior to the time Constantine:
"Diocletian, as being of a timorous disposition, was a searcher into fortune-telling, and during his abode in the East he began to slay victims, that from their livers he might obtain a prognostication of events; and while he sacrificed, some attendants of his, who were Christians, stood by, and they put the immortal sign [of the Cross] on their foreheads. At this the demons were chased away, and the holy rites interrupted. The soothsayers trembled, unable to investigate the wonted marks on the entrails of the victims. They frequently repeated the sacrifices, as if the former had been unpropitious; but the victims, slain from time to time, afforded no tokens for divination. At length Tages, the chief of the soothsayers, either from guess or from his own observation, said, “There are profane persons here, who obstruct the rites.” Then Diocletian, in furious passion, ordered not only all who were assisting at the holy ceremonies, but also all who resided within the palace, to sacrifice, and, in case of their refusal, to be scourged. And further, by letters to the commanding officers, he enjoined that all soldiers should be forced to the like impiety, under pain of being dismissed the service. Thus far his rage proceeded; but at that season he did nothing more against the law and religion of God. After an interval of some time he went to winter in Bithynia; and presently Galerius Cæsar came thither, inflamed with furious resentment, and purposing to excite the inconsiderate old man to carry on that persecution which he had begun against the Christians" (Lactantius: "Of the Manner in Which the Persecutors Died," chapter 10).
While we have no record of exactly when the practice begin, the evidence suggest it either began with the apostles, or very soon after their departure from this life. But without any doubt, the entire Christian Church embraced the practice, and prior to the Protestant Reformation, we have no record that anyone naming the name of Christ ever objected to the practice.
See also:
Christianity Today: Why do liturgical Christians make the sign of the cross?
