1 And now we may well compare the present with former things, and review these happy changes in contrast with the evils that are past, and mark the elaborate care with which in ancient times porches and sacred precincts, groves and temples, were prepared in every city for these false deities, and how their shrines were enriched with abundant offerings.
2. The sovereign rulers of those days had indeed a high regard for the worship of the gods. The nations also and people subject to their power honored them with images both in the country and in every city, nay, even in their houses and secret chambers, according to the religious practice of their fathers. The fruit, however, of this devotion, far different from the peaceful concord which now meets our view, appeared in war, in battles, and seditions, which harassed them throughout their lives, and deluged their countries with blood and civil slaughter.
3. Again, the objects of their worship could hold out to these sovereigns with artful flattery the promise of prophecies, and oracles, and the knowledge of futurity: yet could they not predict their own destruction, nor forewarn themselves of the coming ruin: and surely this was the greatest and most convincing proof of their imposture.
4. Not one of those whose words once were heard with awe and wonder, had announced the glorious advent of the Saviour of mankind, or that new revelation of divine knowledge which he came to give. Not Pythius himself, nor any of those mighty gods, could apprehend the prospect of their approaching desolation; nor could their oracles point at him who was to be their conqueror and destroyer.
5. What prophet or diviner could foretell that their rites would vanish at the presence of a new Deity in the world, and that the knowledge and worship of the Almighty Sovereign should be freely given to all mankind? Which of them foreknew the august and pious reign of our victorious emperor, or his triumphant conquests everywhere over the false demons, or the overthrow of their high places?
6. Which of the heroes has announced the melting down and conversion of the lifeless statues from their useless forms to the necessary uses of men? Which of the gods have yet had power to speak of their own images thus melted and contemptuously reduced to fragments?
7. Where were the protecting powers, that they should not interpose to save their sacred memorials, thus destroyed by man? Where, I ask, are those who once maintained the strife of war, yet now behold their conquerors abiding securely in the profoundest peace? And where are they who upheld themselves in a blind and foolish confidence, and trusted in these vanities as gods; but who, in the very height of their superstitious error, and while maintaining an implacable war with the champions of the truth, perished by a fate proportioned to their crimes?
8. Where is the giant race whose arms were turned against heaven itself; the hissings of those serpents whose tongues were pointed with impious words against the Almighty King? These adversaries of the Lord of all, confident in the aid of a multitude of gods, advanced to the attack with a powerful array of military force, preceded by certain images of the dead, and lifeless statues, as their defense. On the other side our emperor, secure in the armor of godliness, opposed to the numbers of the enemy the salutary and life-giving Sign, as at the same time a terror to the foe, and a protection against every harm; and returned victorious at once over the enemy and the demons whom they served. And then, with thanksgiving and praise, the tokens of a grateful spirit, to the Author of his victory, he proclaimed this triumphant Sign, by monuments as well as words, to all mankind, erecting it as a mighty trophy against every enemy in the midst of the imperial city, and expressly enjoining on all to acknowledge this imperishable symbol of salvation as the safeguard of the power of Rome and of the empire of the world.
9. Such were the instructions which he gave to his subjects generally; but especially to his soldiers, whom he admonished to repose their confidence, not in their weapons, or armor, or bodily strength, but to acknowledge the Supreme God as the giver of every good, and of victory itself.
10. Thus did the emperor himself, strange and incredible as the fact may seem, become the instructor of his army in their religious exercises, and teach them to offer pious prayers in accordance with the divine ordinances, uplifting their hands towards heaven, and raising their mental vision higher still to the King of heaven, on whom they should call as the Author of victory, their preserver, guardian, and helper. He commanded too, that one day should be regarded as a special occasion for religious worship; I mean that which is truly the first and chief of all, the day of our Lord and Saviour; that day the name of which is connected with light, and life, and immortality, and every good.
11. Prescribing the same pious conduct to himself, he honored his Saviour in the chambers of his palace, performing his devotions according to the Divine commands, and storing his mind with instruction through the hearing of the sacred word. The entire care of his household was entrusted to ministers devoted to the service of God, and distinguished by gravity of life and every other virtue; while his trusty body-guards, strong in affection and fidelity to his person, found in their emperor an instructor in the practice of a godly life.
12. Again, the honor with which he regards the victorious Sign is founded on his actual experience of its divine efficacy. Before this the hosts of his enemies have disappeared: by this the powers of the unseen spirits have been turned to flight: through this the proud boastings of God's adversaries have come to nought, and the tongues of the profane and blasphemous been put to silence. By this Sign the Barbarian tribes were vanquished: through this the rites of superstitious fraud received a just rebuke: by this our emperor, discharging as it were a sacred debt, has performed the crowning good of all, by erecting triumphant memorials of its value in all parts of the world, raising temples and churches on a scale of royal costliness, and commanding all to unite in constructing the sacred houses of prayer.
13. Accordingly these signal proofs of our emperor's magnificence immediately appeared in the provinces and cities of the empire, and soon shone conspicuously in every country; convincing memorials of the rebuke and overthrow of those impious tyrants who but a little while before had madly dared to fight against God, and, raging like savage dogs, had vented on unconscious buildings that fury which they were unable to level against him; had thrown to the ground and upturned the very foundations of the houses of prayer, causing them to present the appearance of a city captured and abandoned to the enemy. Such was the exhibition of that wicked spirit whereby they sought as it were to assail God himself, but soon experienced the result of their own madness and folly. But a little time elapsed, when a single blast of the storm of Heaven's displeasure swept them utterly away, leaving neither kindred, nor offspring, nor memorial of their existence among men: for all, numerous as they were, disappeared as in a moment beneath the stroke of Divine vengeance.
14. Such, then, was the fate which awaited these furious adversaries of God: but he who, armed with the salutary Trophy, had alone opposed them (nay rather, not alone, but aided by the presence and the power of him who is the only Sovereign), has replaced the ruined edifices on a greater scale, and made the second far superior to the first. For example, besides erecting various churches to the honor of God in the city which bears his name, and adorning the Bithynian capital with another on the greatest and most splendid scale, he has distinguished the principal cities of the other provinces by structures of a similar kind.
15. Above all, he has selected two places in the eastern division of the empire, the one in Palestine (since from thence the life-giving stream has flowed as from a fountain for the blessing of all nations), the other in that metropolis of the East which derives its name from that of Antiochus; in which, as the head of that portion of the empire, he has consecrated to the service of God a church of unparalleled size and beauty. The entire building is encompassed by an enclosure of great extent, within which the church itself rises to a vast elevation, of an octagonal form, surrounded by many chambers and courts on every side, and decorated with ornaments of the richest kind.
Source: Oration in Praise of Constantine (New Advent)