Constantine  – In 312 A.D., “Constantine was on his march against Maxentius, who had declared war against him, and was in Rome with an army much superior in numbers. The emperor [Constantine] had marched from Rhine, through Gaul, and was going to Rome by way of Verona. He passed the Alp, and was marching with part of his army toward Rome, when, a little before midday, he and those with him saw a bright cross of light in the clouds.” What they saw was a “flaming cross in the sky, and beneath it were the words, in Greek, “In this sign conquer.” He thereupon embraced Christianity.”  “In the night following, Christ appeared to him in his sleep. He had a cross in his hand, and commanded Constantine to have a standard made of it. Next morning the emperor gave orders for such a standard to be made, and called it the Labarum. It was a gilt pole with a cross-bar. The top of the pole was surmounted with a gold crown, set with precious stones, and in the midst a crown were two Greek letters, Chi and Ro (x, p)… From the cross-bar hung a purple veil, strangled and dazzling; the emperor selected fifty of his best men to carry and guard this banner.” He also had the soldiers paint the symbol of a cross on their shields. …

The surrender of Verona was the consequence. In spite of the overwhelming numbers of his enemy (an estimated 100,000 in Maxentius’ army against 20,000 in Constantine’s army) the emperor confidently marched forward to Rome. A vision had assured him that he should conquer in the sign of the Christ, and his warriors carried Christ’s monogram on their shields, though the majority of them were pagans. The opposing forces met near the bridge over the Tiber called the Milvian Bridge, and here Maxentius’ troops suffered a complete defeat, the tyrant himself losing his life in the Tiber (28 October, 312).  ….

If mankind ever needed a sign from God blessing the spread of Christianity, and the Gospel, they were given one on May 7th of 351. Shortly after Cyril had been installed as Archbishop of Jerusalem on the day of Pentecost, a luminous cross appeared in the sky over Jerusalem. “About nine in the morning, a vast luminous body, in the form of a cross, appeared in the heavens, just over the holy Golgotha, reaching as far as the holy Mount of Olivet (about two miles). This was not seen by one or two persons only, but by the whole city, and it continued for several hours, the light from it being more brilliant than that of the sun.” The sign in the sky was a miracle for all to see. It drove Jews, Pagans and Christians alike to churches in praise of Jesus Christ. The luminous cross over Jerusalem was taken as sign by those at the time of God’s approval of the spreading Gospel and expanding Christendom. As St Cyril wrote in his letter to Emperor Constantine, the cross in the sky was “being seen not by one or two only, but manifest with perfect clarity to the whole multitude of the city; not, as one might suppose, rushing swiftly past in fancy, but seen openly above the earth many hours in plain sight, and overcoming the beams of the sun with its dazzling rays.” “The whole city found in this phenomenon the truth of Christian doctrine, to which the heavens bore visible witness.”  

“So swiftly runs the word of God that though in several thousand years God was not known except among the Jews, now within the space of a few years, His word is concealed neither from the Indians in the East nor from the Britain’s in the West.”

— Arnobius of Sicca (284-305) writing from Bethlehem in 378 A.D.