[detch]

Context — Satan was not really a formal name, but something of a name used to describe an “Adversary” of God’s will. By calling Peter Satan, Christ did not mean that Peter was literally the fallen angel Lucifer or one of his minions, but reminding Peter that by not following God's will, he was following the Devil's.

Peter, for his part, was exhorting Jesus not to go to Jerusalem (out of love for Jesus), fearing danger for Jesus.

Jesus knew he would be doing God’s will, going to his execution, and not his own (human) will nor Peter’s (which he even addressed in his own human way in the Garden of Gethsemani, “Lord, take this cup from me.” No Answer. Follow on by Jesus, “Thy will be done.”).

[MHGinTN]

How about this context: Peter taught hypocrisy and was rebuked for it by Paul, publicly (see Galatians). So the ‘so called’ unbroken succession of infallible popery when teaching on faith and or morals is broken with Peter being fallible teaching hypocrisy with his actions and dragging Barnabus along with the hypocrisy.

[Elsie]

By calling Peter Satan, Christ did not mean that Peter was literally the fallen angel

By saying, "This is my body...