The Gospel for this Sunday follows immediately after Peter’s Confession (“You are the Christ, the Son of the Living God”) and Jesus’ appointing Peter to be the first pope of His Church (“You are Peter and, on this Rock, I will build My Church”). Jesus begins to make His first prophecy of the Crucifixion, informing them that He will be arrested, beaten, and killed. This horrifies the Apostles, as one of the beliefs about the Messiah was that he could not die.
   
Peter pulls Jesus aside and remonstrates with Him (I love that phrase), saying, “Lord, this cannot happen to You.” Uncharacteristically, Jesus speaks very harshly to Peter, saying, “Get behind Me, Satan. You are an obstacle.” I can almost hear Peter saying, “Jesus, I am not Satan. I am the pope.”

Jesus has had a previous encounter with the real Satan, in His Temptation in the desert. At that time, Satan was trying to get Jesus to turn away from His mission and to serve His own ego. Peter, unknowingly, was speaking the same message to Jesus, trying to convince Him to not sacrifice Himself to save the world.
   
Jesus also tells Peter, “You are thinking as human beings think, not as God thinks.” Thinking like a human being is the most natural thing in the world for us, being human beings. Conversion means to learn how to think like God. Very challenging task.
--Fr. Mike Comer