7 Let no man therefore be ashamed of the honored symbols of our salvation, and of the chiefest of all good things, whereby we even live, and whereby we are; but as a crown, so let us bear about the cross of Christ. Yea, for by it all things are wrought, that are wrought among us. Whether one is to be new-born, the cross is there; or to be nourished with that mystical food, or to be ordained, or to do anything else, everywhere our symbol of victory is present. Therefore both on house, and walls, and windows, and upon our forehead, and upon our mind, we inscribe it with much care.
For of the salvation wrought for us, and of our common freedom, and of the goodness of our Lord, this is the sign. “For as a sheep was He led to the slaughter.” When therefore you sign yourself, think of the purpose of the cross, and quench anger, and all the other passions. When you sign yourself, fill your forehead with all courage, make your soul free. And ye know assuredly what are the things that give freedom. Wherefore also Paul leading us there, I mean unto the freedom that beseems us, did on this wise lead us unto it, having reminded us of the cross and blood of our Lord. “For you are bought,” says he, “with a price; be not ye the servants of men.” Consider, says he, the price that has been paid for you, and you will be a slave to no man; by the price meaning the cross.
Since not merely by the fingers ought one to engrave it, but before this by the purpose of the heart with much faith. And if in this way you have marked it on your face, none of the unclean spirits will be able to stand near you, seeing the blade whereby he received his wound, seeing the sword which gave him his mortal stroke. For if we, on seeing the places in which the criminals are beheaded, shudder; think what the devil must endure, seeing the weapon, whereby Christ put an end to all his power, and cut off the head of the dragon.
Be not ashamed then of so great a blessing, lest Christ be ashamed of you, when He comes with His glory, and the sign appears before Him, shining beyond the very sunbeam. For indeed the cross comes then, uttering a voice by its appearance, and pleading with the whole world for our Lord, and signifying that no part has failed of what pertained to Him.
This sign, both in the days of our forefathers and now, has opened doors that were shut up; this has quenched poisonous drugs; this has taken away the power of hemlock; this has healed bites of venomous beasts. For if it opened the gates of hell, and threw wide the archways of Heaven, and made a new entrance into Paradise, and cut away the nerves of the devil; what marvel, if it prevailed over poisonous drugs, and venomous beasts, and all other such things.
This therefore do thou engrave upon your mind, and embrace the salvation of our souls. For this cross saved and converted the world, drove away error, brought back truth, made earth Heaven, fashioned men into angels. Because of this, the devils are no longer terrible, but contemptible; neither is death, death, but a sleep; because of this, all that wars against us is cast to the ground, and trodden under foot.
If any one therefore say to you, Do you worship the crucified? Say, with your voice all joy, and your countenance gladdened, “I do both worship Him, and will never cease to worship.” And if he laugh, weep for him, because he is mad. Thank the Lord, that He has bestowed on us such benefits, as one cannot so much as learn without His revelation from above. Why, this is the very reason of his laughing, that “the natural man receives not the things of the Spirit.” Since our children too feel this, when they see any of the great and marvellous things; and if you bring a child into the mysteries, he will laugh. Now the heathen are like these children; or rather they are more imperfect even than these; wherefore also they are more wretched, in that not in an immature age, but when full grown, they have the feelings of babes; wherefore neither are they worthy of indulgence.
But let us with a clear voice, shouting both loud and high, cry out and say (and should all the heathen be present, so much the more confidently), that the cross is our glory, and the sum of all our blessings, and our confidence, and all our crown. I would that also with Paul I were able to say, “By which the world is crucified unto me, and I unto the world;” but I cannot, restrained as I am by various passions.
Source: Homilies on the Gospel of St. Matthew (New Advent)