The Reliability of the Gospel of Mark

For the purposes of this article, reliability will be defined as the number of statements reported by a document which can be judged probable based on the historical evidence. In history, the way in which reliability is measured is incredibly complex because reliability considers the author's
  1. psychological (e.g. carelessness) and biological conditions (e.g. poor eyesite may affect the author's ability to have witnessed events) affecting the author
  2. time and place (e.g. were they in the place for the event they claim to have witnessed)
  3. religion and culture (e.g. the Jewish culture in antiquity had a greater affinity for memorization)
  4. occupation, status, education, and wealth (e.g. wealthier individuals may have greater access to early written materials)
  5. habits and practice in regards to the source material
  6. biases, sentiments, and prejudices which may affect the truthfulness of an account
  7. family, friends, and peers with whom he had contact (e.g. an author who knew an eyewitness may have access to credible information)

Jesus from Nazareth of Galilee

Nazareth, during Jesus' time, was a small village of around one thousand people with little cultural or religious significance. Mark describes Jesus as having been from Nazareth in the beginning of the gospel:
At that time Jesus came from Nazareth in Galilee and was baptized by John in the Jordan [1]
But the more important of the refences for the historian comes later:
Jesus left there and went to his hometown, accompanied by his disciples. When the Sabbath came, he began to teach in the synagogue, and many who heard him were amazed.
Most likely the hometown referred to here is Nazareth, next:
“Where did this man get these things?” they asked. “What’s this wisdom that has been given him? What are these remarkable miracles he is performing? Isn’t this the carpenter? Isn’t this Mary’s son and the brother of James, Joseph, Judas and Simon? Aren’t his sisters here with us?” And they took offense at him. Jesus said to them, “A prophet is not without honor except in his own town, among his relatives and in his own home." [2]
The narrative appears to be an early tradition because of the embarassing elements of the story. The Nazarenes question from where Jesus had received wisdom and miraculous powers since they had known him, and his mother, and father, and brothers, and sisters. They did not believe he was the messiah because the messiah had heavenly (also unknown or origins (in some Jewish circles). But to them, he appeared as though he was merely from earth. So, an early Christian who believed Jesus was the messiah (very likely) and who believed Jesus had heavenly origins (very likely), would have been unlikely to have invented a pericope where the people who had grown up with Jesus and had known him the best were the ones who rejected Jesus' heavenly origin and messianship. Jesus' birthplace is also multiply attested in the gospels: John, [3] Luke, [4] Matthew, [5] and the speeches in Acts. [6] Therefore, the historical evidence supports Mark's claim that Jesus' hometown was Nazareth.

Fishing as a major occupation on the sea of Galilee

The Gospel of Mark names four of the apostles as fishermen: Peter, Andrew, James, and John, sons of Zebedee.
As Jesus walked beside the Sea of Galilee, he saw Simon and his brother Andrew casting a net into the lake, for they were fishermen. “Come, follow me,” Jesus said, “and I will send you out to fish for people.” At once they left their nets and followed him. When he had gone a little farther, he saw James son of Zebedee and his brother John in a boat, preparing their nets. Without delay he called them, and they left their father Zebedee in the boat with the hired men and followed him. [7]
This fact is judge to be likely historically, since we are also told:
Philip was from Bethsaida, the city of Andrew and Peter [8]
Since Bethsaida was a fishing town, and Andrew and Peter were from Bethsaida, it is plausibly from this fact that they were fishermen. But incredibly likely with the fourfold testimony of the gospels.

A synagogue in Capernaum of Galilee

Mark presents Jesus as he,
went to Capernaum, and when the Sabbath came, Jesus went into the synagogue and began to teach. [9]
A synagogue has been found in Capernaum from around the time of Jesus which strengthens the credibility of Mark. [10]