Matthew 16:22

Rebuke him; this showed the self-sufficiency of Peter, his forwardness to express his opinion, and his liability to err.

Shall not be; this was in direct opposition to what Christ had said should be, and what was essential to the salvation of men; showing that Peter was not infallible, but was often wrong. "As with a hammer of iron, Christ here crushes carnal prudence in Peter." We have infallible evidence of the fallibility of Peter, and that he was not, in character, conduct, or authority, above the other apostles.