©Museumslandschaft Hessen Kassel Ute Brunzel/The Bridgeman Art Library

WITH A SOLDIER’S FIRM GRASP on his linen garment, a young man at left escapes naked in this late-16th-century oil-on-panel, The Arrest of Christ by Italian painter Giuseppe Cesari. This short episode is found only in the Gospel of Mark’s account of Jesus’ arrest (Mark 14:51–52), and not in the Gospels of Matthew or Luke, both of whom used Mark’s gospel as a source. A young man wearing only a linen cloth also appears in Secret Mark, as recorded in the Clement letter. Harvard’s Helmut Koester uses details like this, and others, to argue for the authenticity of Secret Mark. His text-critical analysis shows that there were at least two versions of the Gospel of Mark—one earlier and one later—and that Secret Mark fits perfectly into this Marcan textual tradition.