The authorship of the Gospel of Mark is not completely certain, but it is generally attributed to John Mark, an early Greek-speaking Christian living in Rome at the time of his writing.
John Mark would have been educated, as he is referenced by early church leaders as an interpreter for Peter. The Gospel of Mark is believed to be based on the eyewitness accounts of Peter, one of Jesus’s closest disciples. Peter was an uneducated fisherman. John Mark writing down his experiences with Jesus would suggest that he was more educated in some ways than Peter himself.
In his book The New Testament: A Historical Introduction to the Early Christian Writings, Bart Ehrman writes that Mark may have, in addition to Peter’s firsthand account, relied on other existing written materials to create his Gospel. This ability to research, compile evidence, and construct a narrative would also suggest that Mark was educated.
Looking at the Gospel of Mark itself, there is evidence that the author was educated. It is crafted around specific themes and theologies; the “snapshots” of the life of Jesus are concisely written and carefully selected. At some points in the Gospel, Mark explains Aramaic words and phrases for his Greco-Roman audience. Throughout his writing, Mark seeks to familiarize his audience with Jewish customs, particularly with the Jewish concept of “Messiah.” He takes pains to present Jesus as the fulfillment of Messianic promises. The writing techniques in the Gospel of Mark, as well as the bridging between cultures, would imply that the author was widely educated.