Given the apostles’ lack of understanding (see also Acts 1:6), it is likely that in Matthew 16:22, Peter said what all were feeling. Jesus had just called him a rock (Matthew 16:18), due to his confessing Jesus as the Messiah (Matthew 16:16). Perhaps emboldened by this recognition (Matthew 16:17–19), Peter considered suffering unworthy of Jesus. Began to rebuke
implies doing so repeatedly and intensely. Peter literally said, May he ([God]) be gracious to you,
meaning something like God forbid; that must absolutely not happen,
so we see that love without insight can lead us astray (Philippians 1:9). He either did not hear or did not understand the purpose of the passion. Rather than believing Jesus, he wanted, though with good intentions, to be merciful
on his own terms.
How vital the instruction regarding his imminent suffering was is shown by Peter’s response. Given the lack of understanding among the apostles—see also, for example Acts 1:6—we may perhaps again assume that Peter, the passionate one, expressed here in Matthew 16:22 what lived in all of their hearts. Peter had indeed just acknowledged Jesus as the Messiah, but he considered suffering unworthy of him. The apostle either does not hear or he does not understand the purpose of the passion. Rather than believing Jesus, he prefers—albeit with the best intentions—to be merciful
on his own terms and thereby sins by tempting Jesus in a way that recalls even the temptation in the wilderness.1
Peter, who had just moments before uttered such a beautiful confession (Matthew 16:16) and whom Jesus had even called a rock (Matthew 16:18), now became a stumbling stone, an obstacle. Perhaps Peter was now even more emboldened than before in light of the recognition he had just received (Matthew 16:17–19). Began to rebuke
carries the nuance of doing so repeatedly and intensely. Peter literally said, May he [God] be gracious to you,
which means something like God forbid; that must absolutely not happen.
Thus we see that love can lead us astray when it is not accompanied by insight (Philippians 1:9).2
22 And Peter took him aside and began to rebuke him, saying, “Far be it from you, Lord! This shall never happen to you.”