The feast of the Holy Seventy Apostles is celebrated only once a year, on the eve of Epiphany. They are mentioned in only one of the Gospels. Their names are taken from the Acts of the Apostles, the Epistles, and hagiographical accounts, the authors of which did not personally know Christ during his earthly life. This is, perhaps, the main paradox of this celebration.
Dr. Augustine Sokolovski
On the eve of Epiphany, the Orthodox Church celebrates the Synaxis of the Seventy Apostles. Their calling is mentioned in the Gospel of Luke: “After this, the Lord appointed seventy others and sent them out two by two ahead of him to every town and place where he himself was about to go,” proclaims the first verse of chapter 10. This is an extremely important passage, since nothing else in the entire text of the Gospels mentions the selection of the seventy disciples.
A complete list of the seventy apostles has not survived. Medieval hagiographers compiled their own lists based on the traditions of the early churches, the Book of Acts, Paul’s Epistles, the lives of the saints, and the writings of the Church Fathers. However, Western Christianity speaks of seventy-two disciples, while Eastern Christianity counts seventy. This is explained by the fact that these two numbers, seventy and seventy-two, are deeply symbolic and connected to biblical history.
Thus, the prophet Moses chose seventy elders to serve as his assistants. The Sanhedrin of ancient Israel consisted of seventy members. Seventy interpreters translated the Holy Scriptures into Greek. This is the Septuagint, or the Translation of the Seventy Interpreters. The Babylonian captivity of the biblical people lasted seventy years. Since these numbers were almost always recorded as seventy or seventy-two, a discrepancy arose regarding the number of apostles. This is confirmed by the differences among the ancient Gospel manuscripts, which sometimes mention seventy men and sometimes seventy-two men sent by Jesus to preach.
It is important to note that the Eastern Christian tradition preferred to speak of the “seventy apostles,” while the Western Christian tradition spoke of the “seventy disciples.” Among them were the evangelists Mark and Luke. It is Luke, who was one of them himself, who mentions the selection of the seventy in his Gospel. Given that the hagiographic lists of the Seventy also include the names of ancient preachers whom Jesus Himself could hardly have appointed—such as Dionysius the Areopagite—the designation “Seventy Disciples” seems more accurate. It must be acknowledged that the names of many of those whom Jesus sent out to preach have indeed not been preserved. This is a sign of historical humility and evidence that the early Christians lived in such anticipation of the Second Coming that they did not consider it necessary to preserve information for posterity.
The Greek word "Synaxis" in this context denotes a gathering or solemn divine service in honor of a particular event, a saint, or the collective memory of the saints. In the Local Orthodox Churches that follow the Julian calendar, the date of the Feast of the Seventy Apostles is easy to remember thanks to a remarkable combination: The feast of the Seventy Disciples is celebrated by the Church only once a year, on January 17, the eve of the Vigil of the Epiphany, the central theme of which in Orthodoxy is the Baptism of Jesus in the Jordan.