2. For instance the King Abgarus, who ruled with great glory the nations beyond the Euphrates, being afflicted with a terrible disease which it was beyond the power of human skill to cure, when he heard of the name of Jesus, and of his miracles, which were attested by all with one accord sent a message to him by a courier and begged him to heal his disease.
3. But he did not at that time comply with his request; yet he deemed him worthy of a personal letter in which he said that he would send one of his disciples to cure his disease, and at the same time promised salvation to himself and all his house.
4. Not long afterward his promise was fulfilled. For after his resurrection from the dead and his ascent into heaven, Thomas, one of the twelve apostles, under divine impulse sent Thaddeus, who was also numbered among the seventy disciples of Christ, to Edessa, as a preacher and evangelist of the teaching of Christ.
5. And all that our Saviour had promised received through him its fulfillment. You have written evidence of these things taken from the archives of Edessa, which was at that time a royal city. For in the public registers there, which contain accounts of ancient times and the acts of Abgarus, these things have been found preserved down to the present time. But there is no better way than to hear the epistles themselves which we have taken from the archives and have literally translated from the Syriac language in the following manner.
Copy of an epistle written by Abgarus the ruler to Jesus, and sent to him at Jerusalem by Ananias the swift courier.
6. Abgarus, ruler of Edessa, to Jesus the excellent Saviour who has appeared in the country of Jerusalem, greeting. I have heard the reports of you and of your cures as performed by you without medicines or herbs. For it is said that you make the blind to see and the lame to walk, that you cleanse lepers and cast out impure spirits and demons, and that you heal those afflicted with lingering disease, and raise the dead.
7. And having heard all these things concerning you, I have concluded that one of two things must be true: either you are God, and having come down from heaven you do these things, or else you, who does these things, are the Son of God.
8. I have therefore written to you to ask you if you would take the trouble to come to me and heal the disease which I have. For I have heard that the Jews are murmuring against you and are plotting to injure you. But I have a very small yet noble city which is great enough for us both.
The answer of Jesus to the ruler Abgarus by the courier Ananias.
9. Blessed are you who hast believed in me without having seen me. For it is written concerning me, that they who have seen me will not believe in me, and that they who have not seen me will believe and be saved. But in regard to what you have written me, that I should come to you, it is necessary for me to fulfill all things here for which I have been sent, and after I have fulfilled them thus to be taken up again to him that sent me. But after I have been taken up I will send to you one of my disciples, that he may heal your disease and give life to you and yours.
10. To these epistles there was added the following account in the Syriac language. -->After the ascension of Jesus, Judas, who was also called Thomas, sent to him Thaddeus, an apostle, one of the Seventy. When he had come he lodged with Tobias, the son of Tobias. When the report of him got abroad, it was told Abgarus that an apostle of Jesus had come, as he had written him.
11. Thaddeus began then in the power of God to heal every disease and infirmity, insomuch that all wondered. And when Abgarus heard of the great and wonderful things which he did and of the cures which he performed, he began to suspect that he was the one of whom Jesus had written him, saying, 'After I have been taken up I will send to you one of my disciples who will heal you.'
12. Therefore, summoning Tobias, with whom Thaddeus lodged, he said, I have heard that a certain man of power has come and is lodging in your house. Bring him to me. And Tobias coming to Thaddeus said to him, The ruler Abgarus summoned me and told me to bring you to him that you might heal him. And Thaddeus said, I will go, for I have been sent to him with power.
13. Tobias therefore arose early on the following day, and taking Thaddeus came to Abgarus. And when he came, the nobles were present and stood about Abgarus. And immediately upon his entrance a great vision appeared to Abgarus in the countenance of the apostle Thaddeus. When Abgarus saw it he prostrated himself before Thaddeus, while all those who stood about were astonished; for they did not see the vision, which appeared to Abgarus alone.
14. He then asked Thaddeus if he were in truth a disciple of Jesus the Son of God, who had said to him, 'I will send you one of my disciples, who shall heal you and give you life.' And Thaddeus said, Because you have mightily believed in him that sent me, therefore have I been sent unto you. And still further, if you believe in him, the petitions of your heart shall be granted you as you believe.
15. And Abgarus said to him, So much have I believed in him that I wished to take an army and destroy those Jews who crucified him, had I not been deterred from it by reason of the dominion of the Romans. And Thaddeus said, Our Lord has fulfilled the will of his Father, and having fulfilled it has been taken up to his Father. And Abgarus said to him, I too have believed in him and in his Father.
16. And Thaddeus said to him, Therefore I place my hand upon you in his name. And when he had done it, immediately Abgarus was cured of the disease and of the suffering which he had.
17. And Abgarus marvelled, that as he had heard concerning Jesus, so he had received in very deed through his disciple Thaddeus, who healed him without medicines and herbs, and not only him, but also Abdus the son of Abdus, who was afflicted with the gout; for he too came to him and fell at his feet, and having received a benediction by the imposition of his hands, he was healed. The same Thaddeus cured also many other inhabitants of the city, and did wonders and marvelous works, and preached the word of God.
18. And afterward Abgarus said, You, O Thaddeus, do these things with the power of God, and we marvel. But, in addition to these things, I pray you to inform me in regard to the coming of Jesus, how he was born; and in regard to his power, by what power he performed those deeds of which I have heard.
19. And Thaddeus said, Now indeed will I keep silence, since I have been sent to proclaim the word publicly. But tomorrow assemble for me all your citizens, and I will preach in their presence and sow among them the word of God, concerning the coming of Jesus, how he was born; and concerning his mission, for what purpose he was sent by the Father; and concerning the power of his works, and the mysteries which he proclaimed in the world, and by what power he did these things; and concerning his new preaching, and his abasement and humiliation, and how he humbled himself, and died and debased his divinity and was crucified, and descended into Hades, and burst the bars which from eternity had not been broken, and raised the dead; for he descended alone, but rose with many, and thus ascended to his Father.
20. Abgarus therefore commanded the citizens to assemble early in the morning to hear the preaching of Thaddeus, and afterward he ordered gold and silver to be given him. But he refused to take it, saying, If we have forsaken that which was our own, how shall we take that which is another's? These things were done in the three hundred and fortieth year." (taken from non-Orthodox source: http://www.newadvent.org/fathers/250101.htm)
O Holy Apostle Thaddeus, intercede with the merciful God that He grant unto our souls forgiveness of offences.
The Apostle's joyous feast is come with radiant splendour; let us keep it on this day with jubilation and gladness. For to them who ever honour him in sincere faith, it doth grant their sins' forgiveness and true divine health; for he hath great boldness as a divine initiate of Christ's omnipotent grace.