I'll begin with 2 points and later expand them as the discussion proceeds.
(1) Papias (C. 60-125 AD) is famous for his preference for eyewitness testimony ("a living voice") to Jesus over written records. He has directly consulted disciples of the apostles and even a couple of living disciplesof Jesus (John the Elder and Aristion). What he learns is that the Gospel of Mark is based on Peter's teaching ministry and is therefore on eyewitness testimony. Mark is criticized by these disciples for changing the sequence of events in Jesus' life. Mark does not offer a chronologically historical narration, but rather on how each story fits his thematic purpose. This explains why Jesus' itinerary in Mark makes little sense as a continuous journey. So it is irresponsible to claim that Mark is poorly informed about Palestinian geography. Mark's role as Peter's assistant and translator is attested in 1 Peter 5:13. Peter was martyred in Rome and the Latanisms in Mark attest Rome as the place of the Gospel's origin. So the Gospel's origin in Rome attests its connection to eyewitness testimony (Peter's). This fits nicely with Justin Martyr's reference in Rome to Mark's Gospel as "his (Peter's) memoirs (Dialogue with Trypho 106:3)."
(2) The historical credibility of Mark's preservation of Peter's memoirs can be supported by striking details that are embarrassing and unlikely to be fabricated. Here are just 3 examples: (a) The Gospel concedes that Jesus' family considers him mad and actually tries to physically restrain Him (3:19-21). This rejection prompts Jesus to complain that no prophet is "honored among his own kin and in his own house (6:4)." Even John 7:5 sadly concedes, "His own brothers did not believe in Him." (b) Hostility at Nazareth creates an atmosphere in which Jesus "is unable" to perform miracles there. In other words, He apparently tries and fails! (The "except" clause in Mark 6:6 is recognized by scholars as a later gloss.). (c) Jesus does not succeed in curing the blind man at Bethsaida on His first attempt. A 2nd effort is needed to complete the healing (8:22-26). These embarrassing details are surely historical reminiscences.
(1) Papias (C. 60-125 AD) is famous for his preference for eyewitness testimony ("a living voice") to Jesus over written records. He has directly consulted disciples of the apostles and even a couple of living disciplesof Jesus (John the Elder and Aristion). What he learns is that the Gospel of Mark is based on Peter's teaching ministry and is therefore on eyewitness testimony. Mark is criticized by these disciples for changing the sequence of events in Jesus' life. Mark does not offer a chronologically historical narration, but rather on how each story fits his thematic purpose. This explains why Jesus' itinerary in Mark makes little sense as a continuous journey. So it is irresponsible to claim that Mark is poorly informed about Palestinian geography. Mark's role as Peter's assistant and translator is attested in 1 Peter 5:13. Peter was martyred in Rome and the Latanisms in Mark attest Rome as the place of the Gospel's origin. So the Gospel's origin in Rome attests its connection to eyewitness testimony (Peter's). This fits nicely with Justin Martyr's reference in Rome to Mark's Gospel as "his (Peter's) memoirs (Dialogue with Trypho 106:3)."
(2) The historical credibility of Mark's preservation of Peter's memoirs can be supported by striking details that are embarrassing and unlikely to be fabricated. Here are just 3 examples: (a) The Gospel concedes that Jesus' family considers him mad and actually tries to physically restrain Him (3:19-21). This rejection prompts Jesus to complain that no prophet is "honored among his own kin and in his own house (6:4)." Even John 7:5 sadly concedes, "His own brothers did not believe in Him." (b) Hostility at Nazareth creates an atmosphere in which Jesus "is unable" to perform miracles there. In other words, He apparently tries and fails! (The "except" clause in Mark 6:6 is recognized by scholars as a later gloss.). (c) Jesus does not succeed in curing the blind man at Bethsaida on His first attempt. A 2nd effort is needed to complete the healing (8:22-26). These embarrassing details are surely historical reminiscences.