1 Much might indeed be said of this salutary Sign, by those who are skilled in the mysteries of our Divine religion. For it is in very truth the symbol of salvation, wondrous to speak of, more wondrous still to conceive; the appearance of which on earth has thrown the fictions of all false religion from the beginning into the deepest shade, has buried superstitious error in darkness and oblivion, and has revealed to all that spiritual light which enlightens the souls of men, even the knowledge of the only true God.
2. Hence the universal change for the better, which leads men to spurn their lifeless idols, to trample under foot the lawless rites of their demon deities, and laugh to scorn the time-honored follies of their fathers. Hence, too, the establishment in every place of those schools of sacred learning, wherein men are taught the precepts of saving truth, and dread no more those objects of creation which are seen by the natural eye, nor direct a gaze of wonder at the sun, the moon, or stars; but acknowledge him who is above all these, that invisible Being who is the Creator of them all, and learn to worship him alone.
3. Such are the blessings resulting to mankind from this great and wondrous Sign, by virtue of which the evils which once existed are now no more, and virtues heretofore unknown shine everywhere resplendent with the light of true godliness.
4. Discourses, and precepts, and exhortations to a virtuous and holy life, are proclaimed in the ears of all nations. Nay, the emperor himself proclaims them: and it is indeed a marvel that this mighty prince, raising his voice in the hearing of all the world, like an interpreter of the Almighty Sovereign's will, invites his subjects in every country to the knowledge of the true God.
5. No more, as in former times, is the babbling of impious men heard in the imperial palace; but priests and pious worshipers of God together celebrate his majesty with royal hymns of praise. The name of the one Supreme Ruler of the universe is proclaimed to all: the gospel of glad tidings connects the human race with its Almighty King, declaring the grace and love of the heavenly Father to his children on the earth.
6. His praise is everywhere sung in triumphant strains: the voice of mortal man is blended with the harmony of the angelic choirs in heaven; and the reasoning soul employs the body which invests it as an instrument for sounding forth a fitting tribute of praise and adoration to his name. The nations of the East and the West are instructed at the same moment in his precepts: the people of the Northern and Southern regions unite with one accord, under the influence of the same principles and laws, in the pursuit of a godly life, in praising the one Supreme God, in acknowledging his only begotten Son their Saviour as the source of every blessing, and our emperor as the one ruler on the earth, together with his pious sons.
7. He himself, as a skillful pilot, sits on high at the helm of state, and directs the vessel with unerring course, conducting his people as it were with favoring breeze to a secure and tranquil haven. Meanwhile God himself, the great Sovereign, extends the right hand of his power from above for his protection, giving him victory over every foe, and establishing his empire by a lengthened period of years: and he will bestow on him yet higher blessings, and confirm in every deed the truth of his own promises. But on these we may not at present dwell; but must await the change to a better world: for it is not given to mortal eyes or ears of flesh, fully to apprehend the things of God.
Source: Oration in Praise of Constantine (New Advent)