Ephraim came from Amidene and was a count when Justinus the Thracian was reigning in 518. He came to Antioch to rebuild it because it had been destroyed by earthquakes for a second time. By royal command he was consecrated bishop by the people of Antioch in 527 as Meletios writes and as it had happened in times of old with Ambrosios of Mediolana (Milan) and Nectarios of Constantinople.
Ephraim was a great enemy of the Monophysites. So, he wrote strongly against them, as Photios says. He heard that there was stylite monk in Hierapolis who was a follower of Severus the monophysite. So, he was moved by holy zeal, went to him and started teaching him the orthodox faith. But the monk was not at all convinced by his words. So, the monk said: "Let us both get into the fire and whosoever is not harmed by the flame is orthodox and victorious." He said these words in order to scare Ephraim away. But Ephraim said: "Bring here wood and fire and I shall get into it resting all my courage on omnipotent God. So, you, too, descend from your pillar." But the monk did not want to come down. Then, Ephraim took his overcoat off, prayed and threw both himself and his overcoat onto the fire. Miraculously the fire was immediately put out and he and his overcoat remained unharmed and unburnt. When the monk saw this miracle, he came down from his pillar and anathematized Severus' heresy. Thus, the monk was united with the catholic Church.
These things are told by Sophronios, Patriarch of Jerusalem.
Because Antioch had been ruined by earthquakes for a second time, as we have said above, the fear of earthquake made every Christian write on his homedoor these words: "May Christ stand with us." So, because of this Antioch was called Theoupolis (God's city) as Nicephoros relates in book xvii of his history.