Saint Clement of Alexandria1 assures us that this saint was one of the seventy-two disciples confirmed by Eusebius and Saint Jerome. We learn from the Acts of the apostles that he was a constant attendant on our Lord from the time of his baptism by Saint John to his ascension. Saint Peter declared the necessity of choosing a twelfth apostle. Two were unanimously pitched upon by the assembly, as most worthy of the dignity, Joseph, called Barsabas, and Matthias. After devout prayer to God they proceeded in it by way of lot and Matthias was accordingly associated with the eleven and ranked among the apostles.

Saint Matthias received the Holy Ghost with the rest soon after applied himself with zeal to the functions of his apostleship. He is recorded by Saint Clement of Alexandria to have been remarkable for inculcating the necessity of the mortification of the flesh with regard to all its sensual and irregular desires an important lesson he had received from Christ, and which he practiced assiduously on his own flesh. Saint Matthias planted the faith about Cappadocia and on the coasts of the Caspian sea.

The Latins keep his festival on the 24th of February. Some portions of his relics are shown in the abbatical church of Triers.