The Greek word martus signifies a witness who testifies to a fact of which he has knowledge from personal observation. It is in this sense that the term first appears in Christian literature; the Apostles were "witnesses" of all that they had observed in the public life of Christ, as well as of all they had learned from His teaching, "in Jerusalem, and in all Judea, and Samaria, and even to the uttermost part of the earth" (Acts 1:8). St. Peter, in his address to the Apostles and disciples relative to the election of a successor to Judas, employs the term with this meaning: "Wherefore, of these men who have accompanied with us all the time that the Lord Jesus came in and went out among us, beginning from the baptism of John until the day he was taken up from us, one of these must be made witness with us of his resurrection" (Acts 1:22).
In his first public discourse the chief of the Apostles speaks of himself and his companions as "witnesses" who saw the risen Christ and subsequently, after the miraculous escape of the Apostles from prison, when brought a second time before the tribunal, Peter again alludes to the twelve as witnesses to Christ, as the Prince and Saviour of Israel, Who rose from the dead; and added that in giving their public testimony to the facts, of which they were certain, they must obey God rather than man (Acts 5:29 sqq.). In his First Epistle St. Peter also refers to himself as a "witness of the sufferings of Christ" (1 Peter 5:1).
But even in these first examples of the use of the word martus in Christian terminology a new shade of meaning is already noticeable, in addition to the accepted signification of the term. The disciples of Christ were no ordinary witnesses such as those who gave testimony in a court of justice. These latter ran no risk in bearing testimony to facts that came under their observation, whereas the witnesses of Christ were brought face to face daily, from the beginning of their apostolate, with the possibility of incurring severe punishment and even death itself. Thus, St. Stephen was a witness who early in the history of Christianity sealed his testimony with his blood. The careers of the Apostles were at all times beset with dangers of the gravest character, until eventually they all suffered the last penalty for their convictions. Thus, within the lifetime of the Apostles, the term martus came to be used in the sense of a witness who at any time might be called upon to deny what he testified to, under penalty of death.
