Returning to Mark’s gospel, we pick up our study immediately after Peter’s confession in Caesarea Philippi of Jesus as the Christ—the promised Messiah (Mark 8:27–29). As we have seen, Jesus did not correct Peter’s confession, though He ordered the Twelve not to tell anyone about it. Instead, He began teaching them that His messianic vocation would entail His suffering, death, and resurrection (vv. 30–32a).
However, though Jesus did not correct Peter’s confession in itself, He soon had to correct Peter regarding the disciple’s understanding of what his confession meant. When Peter objected to Christ’s definition of what the Messiah would have to do, Jesus rebuked him and accused him of speaking the things of Satan and not the things of God (vv. 32b–33). The implication is clear—to resist Jesus’ teaching is to act as a disciple of Satan, and this is true regardless of whether the person making the objection understands what he is saying.
Many errors derive from sheer malice, whereas other errors have the best of intentions behind them. Our Lord’s rebuke of Peter shows us that good intentions do not excuse falsehood. God does not give sin a pass even when it is well-intentioned. John Calvin comments that in this episode, “we learn what estimation in the sight of God belongs to what are called good intentions. . . . Certainly, if the feeling and judgment of the flesh be admitted, Peter’s intention was pious, or at least it looked well. And yet Christ could not have conveyed his censure in harsher or more disdainful language. . . . Christ reproves it so sharply, and bruises it, as it were, with an iron hammer, to teach us that it is only from the word of God that we ought to be wise.” Peter did not mean to miss the point of Jesus’ coming. He resisted our Lord’s teachings with the best of motives, desiring to help Jesus understand who the Messiah was supposed to be. But his motive was irrelevant to the issue at hand. Peter had made a huge blunder, and he needed quick instruction to break out of his error.
As one commentator notes, the sharpness of Jesus’ rebuke to Peter also shows us that half-truths can be worse than outright errors. Peter was correct that Jesus was the Messiah; he was wrong about what that would mean. Even for those grounded in sound doctrine, half-truths such as Peter’s are much harder to spot than outright denials of Jesus’ identity, making it imperative that we use precise language in our theological discussions.