Saint Thaddeus, Apostle of the Seventy, was by descent a Hebrew, and he was born in the Syrian city of Edessa. The holy Apostle Thaddeus of the Seventy must be distinguished from Saint Jude, also called Thaddeus or Levi (June 19), who was one of the Twelve Apostles.
When he came to Jerusalem for a feastday, he heard the preaching of John the Forerunner. After being baptized by him in the Jordan, he remained in Palestine. He saw the Savior, and became His follower. He was chosen by the Lord to be one of the Seventy Disciples, whom He sent by twos to preach in the cities and places where He intended to visit (Luke. 10: 1).
After the Ascension of the Savior to Heaven, Saint Thaddeus preached the good news in Syria and Mesopotamia. He came preaching the Gospel to Edessa and he converted King Abgar, the people and the pagan priests to Christ. He backed up his preaching with many miracles (about which Abgar wrote to the Assyrian emperor Nerses). He established priests there and built up the Edessa Church.
Prince Abgar wanted to reward Saint Thaddeus with rich gifts, but he refused and went preaching to other cities, converting many pagans to the Christian Faith. He went to the city of Beirut to preach, and he founded a church there. It was in this city that he peacefully died in the year 44. (The place of his death is indicated as Beirut in the Slavonic MENAION, but according to other sources he died in Edessa. According to an ancient Armenian tradition, Saint Thaddeus, after various tortures, was beheaded by the sword on December 21 in the Artaz region in the year 50).
The Apostle Thaddaeus was from Edessa, a Jew by race. When he came to Jerusalem, he became a disciple of Christ, and after His Ascension he returned to Edessa. There he catechized and baptized Abgar (see Aug. 16). Having preached in Mesopotamia, he ended his life in martyrdom. Though some call him one of the Twelve, whom Matthew calls “Lebbaeus, whose surname was Thaddaeus” (Matt. 10:3), Eusebius says that he is one of the Seventy: “After [Christ’s] Resurrection from the dead, and His ascent into Heaven, Thomas, one of the twelve Apostles, inspired by God, sent Thaddaeus, one of the seventy disciples of Christ, to Edessa as a preacher and evangelist of Christ’s teaching” (Eccl. Hist. 1: 13).
This Thaddaeus was one of the Seventy Apostles, but was not the Thaddaeus who was one of the Twelve Apostles. St. Thaddaeus first encountered John the Baptist and received baptism from him; then he found the Lord Jesus and followed Him. The Lord numbered him among the Seventy Lesser Apostles, whom He sent out two by two before His face: After these things, the Lord appointed other seventy also and sent them two and two before His face into every city and place where He Himself would come (Luke 10:1). After His glorious Resurrection and His Ascension, the Lord sent Thaddaeus to Edessa, Thaddaeus’s birthplace, according to the promise He gave to Prince Abgar when He returned Abgar’s towel with the image of His face on it (the Icon of the Lord “Not Made With Hands,” August 16). By kissing the towel, Abgar was healed of leprosy, but not completely.
[A little leprosy still remained on his face.] When St. Thaddaeus appeared to Abgar, he received him with great joy. The apostle of Christ instructed him in the true Faith, and after that baptized him. When Abgar arose out of the baptismal water, he was completely healed. Glorifying God, Prince Abgar also determined that his people should know the true God and glorify Him. The prince assembled all the citizens of Edessa before the holy Apostle Thaddaeus to hear his teaching about Christ.
Hearing the words of the apostle and seeing their prince miraculously healed, the people rejected their former idolatry and unclean living, embraced the Christian Faith, and were baptized. Thus the city of Edessa was illumined by the Christian Faith. Prince Abgar brought much gold and offered it to the apostle, but Thaddaeus said to him: ” Since we left our own gold, how can we receive the gold of others?” St. Thaddaeus preached the Gospel throughout Syria and Phoenicia. He reposed in the Lord in the Phoenician city of Beirut.
Apolytikion of Holy Apostle Thaddaeus
O Holy Apostle Thaddeus, intercede to our merciful God, that He may grant our souls forgiveness of sins.
Kontakion of Holy Apostle Thaddaeus
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.
Source: oca.org / goarch.org/ westserbdio.org