Mark the Evangelist
It is widely accepted that this saint, the writer of the first gospel, is John Mark, cousin of Barnabas, and companion of Paul and Barnabas in the book of Acts (Acts 12:12 and 25). Many scholars believe that Mark was also the "young man" who followed Jesus after his arrest:
"A certain young man was following him, wearing nothing but a linen cloth. They caught hold of him, but he left the linen cloth and ran off naked."
- Mark 14:15-16, NRSV
The gospel of Mark dates to about A.D. 70. Mark's is the shortest gospel, telling Jesus' story simply and directly. It begins with John the Baptist and ends with the women visiting Jesus' empty tomb.
(This image of Mark is detail from a statue by Donatello in Florence, 1411.)