Mark shows no first-hand understanding of the social situation in Palestine. He is clearly a foreigner, removed both in space and time from the events he alleges. For example, in Mark 10:12, he has Jesus say that if a woman divorces her husband and marries another, she commits adultery. As G. A. Wells, the author of The Historical Evidence for Jesus 10 puts it,
Such an utterance would have been meaningless in Palestine, where only men could obtain divorce. It is a ruling for the Gentile Christian readers... which the evangelist put into Jesus' mouth in order to give it authority. This tendency to anchor later customs and institutions to Jesus' supposed lifetime played a considerable role in the building up of his biography.
One further evidence of the inauthenticity of Mark is the fact that in chapter 7, where Jesus is arguing with the Pharisees, Jesus is made to quote the Greek Septuagint version of Isaiah in order to score his debate point. Unfortunately, the Hebrew version says something different from the Greek. Isaiah 29:13, in the Hebrew reads "their fear of me is a commandment of men learned by rote," whereas the Greek version - and the gospel of Mark - reads "in vain do they worship me, teaching as doctrines the precepts of men" [Revised Standard Version). Wells observes dryly [p. 13], "That a Palestinian Jesus should floor Orthodox Jews with an argument based on a mistranslation of their scriptures is very unlikely." Indeed!
Another powerful argument against the idea that Mark could have been an eye-witness of the existence of Jesus is based upon the observation that the author of Mark displays a profound lack of familiarity with Palestinian geography. If he had actually lived in Palestine, he would not have made the blunders to be found in his gospel. If he never lived in Palestine, he could not have been an eye-witness of Jesus. You get the point.
The most absurd geographical error Mark commits is when he tells the tall tale about Jesus crossing over the Sea of Galilee and casting demons out of a man (two men in Matthew's revised version) and making them go into about 2,000 pigs which, as the King James version puts it, "ran violently down a steep place into the sea... and they were choked in the sea."
Apart from the cruelty to animals displayed by the lovable, gentle Jesus, and his disregard for the property of others, what's wrong with this story? If your only source of information is the King James Bible, you might not ever know. The King James says this marvel occurred in the land of the Gadarenes, whereas the oldest Greek manuscripts say this miracle took place in the land of the Gerasenes. Luke, who also knew no Palestinian geography, also passes on this bit of absurdity. But Matthew, who had some knowledge of Palestine, changed the name to Gadarene in his new, improved version; but this is further improved to Gergesenes in the King James version.
By now the reader must be dizzy with all the distinctions between Gerasenes, Gadarenes, and Gergesenes. What difference does it make? A lot of difference, as we shall see.
Gerasa, the place mentioned in the oldest manuscripts of Mark, is located about 31 miles from the shore of the Sea of Galilee! Those poor pigs had to run a course five miles longer than a marathon in order to find a place to drown! Not even lemmings have to go that far. Moreover, if one considers a "steep" slope to be at least 45 degrees, that would make the elevation of Gerasa at least six times higher than Mt. Everest!
When the author of Matthew read Mark's version, he saw the impossibility of Jesus and the gang disembarking at Gerasa (which, by the way, was also in a different country, the so-called Decapolis). Since the only town in the vicinity of the Sea of Galilee that he knew of that started with G was Gadara, he changed Gerasa to Gadara. But even Gadara was five miles from the shore - and in a different country. Later copyists of the Greek manuscripts of all three pig-drowning gospels (Matthew, Mark, and Luke) improved Gadara further to Gergesa, a region now thought to have actually formed part of the eastern shore of the Sea of Galilee. So much for the trustworthiness of the biblical tradition.
Another example of Mark's abysmal ignorance of Palestinian geography is found in the story he made up about Jesus traveling from Tyre on the Mediterranean to the Sea of Galilee, 30 miles inland. According to Mark 7:31, Jesus and the boys went by way of Sidon, 20 miles north of Tyre on the Mediterranean coast! Since to Sidon and back would be 40 miles, this means that the wisest of all men walked 70 miles when he could have walked only 30. Of course, one would never know all this from the King James version which - apparently completely ignoring a perfectly clear Greek text - says "Departing from the coasts of Tyre and Sidon, he came unto the Sea of Galilee..." Apparently the translators of the King James version also knew their geography. At least they knew more than did the author of Mark!