3 John 1:1
1 The elder unto the wellbeloved Gaius, whom I love ina the truth.
THE THIRD EPISTLE OF
S. JOHN..
1. To Gaius, the Greek form of Caius. Who was this Caius? Lucius Dextor in his "Chronicle" thinks he was the son of Caius Oppius, the centurion. He thus writes concerning him: "S. John the Theologian wrote from Ephesus to the Spaniard Caius, the son of Caius Malacitanus, the centurion, and brother of Demetrius, a hospitable man, whose father was afterwards Bishop of Milan. Now Diotrephes hindered the guests who were coming into the Spains for the sake of pilgrimage. This wicked bishop was afterwards deposed on account of his crimes and his pride. There was a pilgrimage from many other places to the holy places of Spain from the very times of the Apostles, when Caius Oppius the centurion supported the pilgrims. This Caius was domiciled at Corinth, but of Spanish descent. He also liberally entertained in his house the blessed Paul when he was returning from Spain, and he invited John when he was going redeuntim into Spain after his exile. He accompanied John, and was at Rome until the time of Hyginus. After that he went to Milan, and being made Bishop there died in the Lord." So also Onuphrius in his "Chronicle" makes Caius the third Bishop of Milan. But he says he was a Roman, not a Spaniard.
2. Bede, the Gloss, Ambrosiaster, and many others think that this Caius was the Corinthian, of whom S. Paul, writing from Corinth to the Romans, says (Rom 14:23), "Gaius, wine host and of the whole Church " (as Bede and the Greek read), "salutes you." This was because of his hospitality in receiving any members of the Church into his house. In like manner, S. John here warmly commends this Caius for his hospitality. S. Paul also says of Caius (1 Corinthians 1:14), "I baptized none of you save Crispus and Gaius." Moreover, S. Athanasius, in his Synopis, testifies that this Caius was an intimate friend of S. John's, and that he wrote his Gospel at S. John's dictation.
Mariana and Serarius add that this Caius is the same as he to whom four Epistles of S. Dionysius the Areopagite are extant. They are inscribed to Caius the Therapeutes, i.e. the Essene, or monk. It is considered to favour this idea that S. John writes to his Caius in ver. 11, "He that doeth good is of God: he that doeth not good hath not seen God." For the Therapeutæ, giving themselves up continually to pious contemplation, by this means saw God. From hence they were called Seers, like the Prophets of old.