Here are three early church fathers who provide reliable, authoritative and independent confirmation that Mark's Gospel is based on the testimony of the apostle Peter.
These testimonies are all written within 40 to 130 years of the earliest possible date for the death of Mark.
Dates for the publication of the Gospel of Mark itself range from c.40 to 70 AD. So these testimonies for the origin of Mark's Gospel are all given within a range of 40 to 160 years of its publication. That is extraordinarily early unanimous independent testimony for its origin. I am unaware of any other ancient document that has this kind of testimony to its provenance.
The apostle John via Papias, a disciple of the apostle John (writing c.110):
"And the Elder [the apostle John] used to say this: 'Mark, having become Peter’s interpreter, wrote down accurately everything he remembered, though not in order, of the things either said or done by Christ. For he neither heard the Lord nor followed him, but afterward, as I said, followed Peter, who adapted his teaching as needed but had no intention of giving an ordered account of the Lord’s sayings. Consequently, Mark did nothing wrong in writing down some things as he remembered them, for he made it his one concern not to omit anything which he had heard, or to make any false statements in them.' Such, then, is the account given by Papias with respect to Mark" (from Papias' 5-volume work The Exposition of the Oracles of the Lord as recorded in Eusebius' Church History 3.39)
*for more on Papias, see my blog article: The Importance of Papias, The Disciple of the Apostle John
Justin Martyr (writing c.132-165):
“And when it is said that He changed the name of one of the apostles to Peter; and when it is written in the memoirs of him that this so happened, as well as that He changed the names of other two brothers, the sons of Zebedee, to Boanerges, which means sons of thunder. . ." (Dialogue with Trypho 106). Compare this with Mark 3:16-17: "These are the twelve he appointed: Simon (to whom he gave the name Peter), 17 James son of Zebedee and his brother John (to them he gave the name Boanerges, which means “sons of thunder”),...." This is found only in the Gospel of Mark and not in the other three New Testament Gospels or any of the gnostic or apocryphal writings (including the Gospel of Peter that some have carelessly attributed as the source of Justin's statement).
Clement of Alexandria, who assumed leadership of the catechetical school founded by Mark at Alexandria (Clement assumed leadership of this "seminary" and wrote c.180-200):
"But so great a light of godliness shone upon the minds of Peter’s listeners that they were not satisfied with a single hearing or with the oral teaching of the divine proclamation. So, with all kinds of exhortations they begged Mark (whose Gospel is extant), since he was Peter’s follower, to leave behind a written record of the teaching given to them verbally, and did not quit until they had persuaded the man, and thus they became the immediate cause of the Scripture called “The Gospel According to Mark.” And they say that the apostle, aware of what had occurred because the Spirit had revealed it to him, was pleased with their zeal and sanctioned the writing for study in the churches. Clement (of Alexandria) quotes the story in the sixth book of Hypotyposes, and the bishop of Hierapolis, named Papias, corroborates him" (Eusebius' Church History 2.15).
From this we can conclude that the Gospel of Mark is based faithfully and accurately on the eyewitness testimony of the Apostle Peter as written down by his beloved assistant Mark (1 Peter 5:13: "my son Mark"). And note that the Apostle John is emphatic that Mark "made it his one concern not to omit anything which he had heard, or to make any false statements in them."
Flemish School (c. 1600), Christ Calling Saint Peter (public domain via Wikimedia Commons)
