What does Mark 14:70 mean?
Peter's world is spiraling out of control. He followed Jesus to Jerusalem knowing it might be dangerous (John 11:8, 16), but the week has been empowering. Jesus has spent days in the temple courtyard, teaching the adoring crowds and shutting down the religious and civil leaders (Mark 11:27—12:40). Although Jesus prophesies His death and the abandonment of the disciples (Mark 10:32–34; 14:27), the disciples still anticipate He will free the Jews from Roman rule and they will judge in His kingdom (Matthew 19:28).Earlier that night, however, servants and guards from the high priest came to their campsite in the garden of Gethsemane to arrest Jesus (Mark 14:43–50). In the chaos, Peter draws his sword and cuts off the ear of one of the servants (John 18:1–11). John, who knows the high priest, is in the courtyard where the Sanhedrin is harassing and beating Jesus as they try to find something to convict Him of (John 18:15; 18:22). Peter is in a lower courtyard, trying to hide the fact that he is not an innocent bystander. Unfortunately, his Galilean accent gives him away.
This detail is not included by Mark to make any particular spiritual point. That said, our "accent" should also identify us as Christ-followers. The way we speak and act, and how we love other believers, should lead the world to know that we accept Jesus' sacrifice for the payment of our sins and that we strive to live in the grace and power that marks Jesus' character. When we take our eyes off Jesus and act impulsively, as Peter did, we not only endanger ourselves, we make Jesus look bad. Paul warns the Romans about judging the sins of others while we commit the same sins (Romans 2:17–23) ending with, "For, as it is written, 'The name of God is blasphemed among the Gentiles because of you'" (Romans 2:24).