Peter was an eyewitness of practically all that Mark recorded, so he could have learned from Peter many descriptive points that are lacking in the other Gospels. For example, Mark speaks of “the hired men” that worked for Zebedee, the leper entreating Jesus “on bended knee,” the demonized man “slashing himself with stones,” and Jesus’ giving his prophecy about the ‘coming of the Son of man with great power and glory’ while he was sitting on the Mount of Olives “with the temple in view.”​—Mark 1:20, 40; 5:5; 13:3, 26.

Mark evidently wrote primarily for the Romans. How do we know this? The Law of Moses is mentioned only when reporting conversation that referred to it, and the genealogy of Jesus is left out. The gospel of Christ is represented as of universal importance. He makes explanatory comments on Jewish customs and teachings with which non-Jewish readers might be unfamiliar. (2:18; 7:3, 4; 14:12; 15:42) Aramaic expressions are translated. (3:17; 5:41; 7:11, 34; 14:36; 15:22, 34) He qualifies Palestinian geographic names and plant life with explanations. (1:5, 13; 11:13; 13:3) The value of Jewish coins is given in Roman money. (12:42, footnote) He uses more Latin words than the other Gospel writers, examples being speculator (body guardsman), praetorium (governor’s palace), and centurio (army officer).​—6:27; 15:16, 39.