Mark 8:31-33 He then began to teach them that the Son of Man must suffer many things and be rejected by the elders, chief priests and teachers of the law, and that he must be killed and after three days rise again. He spoke plainly about this, and Peter took him aside and began to rebuke him. But when Jesus turned and looked at his disciples, he rebuked Peter. “Get behind me, Satan!” he said. “You do not have in mind the things of God, but the things of men.”
The above scriptures follow Peter's proclamation: "You are the Christ," which Jesus said was inspired by God: “Blessed are you, Simon son of Jonah, for this was not revealed to you by man, but by my Father in heaven. And I tell you that you are Peter, and on this rock I will build my church, and the gates of Hades will not overcome it. I will give you the keys of the kingdom of heaven; whatever you bind on earth will be bound in heaven, and whatever you loose on earth will be loosed in heaven." (Matthew 16:17-19) However, immediately after Peter proclaimed those blessed words, Jesus rebukes Peter, stating he is in league with Satan himself. How could this happen? One moment Peter is mouthing the words of God; the next moment Jesus denounces him an instrument of the devil. Is this possible that Jesus plans to build his church upon Peter's confession of faith, and Peter suddenly puts himself in the enemy's camp? Yes, this spiritual confusion and double mindedness is the inimical condition of the human race. We want God and his blessings, but we often want them for our own purposes and not his eternal plan. We want his presence to embellish our own lives, to do what we need, to fulfill our wants. We want him to bless our dimensions and view of reality: sight, hearing, touch, smell, and taste. We want God in our kingdom, not necessarily in his kingdom. Our self-interests and desires many times trump his reality and purposes. Peter was not a bad person in his own eyes when he rebuked Jesus for saying He must die and rise again, yet he was completely outside of the will of God. In Christ's view, at that moment Peter was in league with Satan.
Peter loved the Lord passionately. As we see later on in his life, Peter is fearless. Probably the reason Peter with his comrades James and John were always near Jesus in difficult places was that Jesus could trust Peter. He was a rough man on the outside, yet full of passion, even ready to die for his Lord. We see Peter in the Garden defending Jesus with a sword. At that time he intended to die with Jesus, for they were seriously outnumbered; and when Jesus told him to put away the sword, Peter was dismayed. Peter must have thought, How can I defend this Jesus without my sword? How can I have his back if He will not fight for himself? Consequently, Peter merely followed Jesus into the courtyard of the High Priest; and then when confronted as a follower of Jesus, he denies knowing him. All of this story reveals why Jesus rebuked Peter: Get behind me, Satan!” he said. “You do not have in mind the things of God, but the things of men.” Peter was willing to fight for a kingdom he could image with his natural mind: the restoration of the Jewish nation. But, he was not willing to fight for a kingdom he could not perceive by his senses. He could surmise easily that Jesus as the Messiah, the anointed one who could bring back the glory days of the Jewish people; but his spiritual eyes could not conceive of a Messiah led away by soldiers to die. But Jesus called his perception earthly, evil. Peter wanted a kingdom for himself and his people: he was willing to die for that. But Jesus told him he did not understand the realities of God's kingdom. Jesus was saying, Peter, your mind is centered on this world, on the temporary things of this world and not on God's plans. God is establishing another kingdom, an incorruptible kingdom that will never end, where there will be no more sorrow and sickness, and death will pass away.
Jesus said, If anyone would come after me, he must deny himself and take up his cross daily and follow me. For whoever wants to save his life will lose it, but whoever loses his life for me will save it. (Matthew 16:24-25) Dying to the flesh and living for Christ is the central theme of the New Testament. Those who want to establish a kingdom of niceties here for themselves are diametrically opposed to the purposes of God. As with Peter and his idealistic panoramic view of life, Jesus says, Get behind me, Satan! Jesus illustrates true faith in God's kingdom in his comment about the widow's mite when He says she put in everything — all she had to live on when she gave her two coins worth less than a penny. (See Mark 12:42-43) For her this world was not her home. Jesus tells us the rich young man could not sell everything and give it to the poor, for this world was still his home. Jesus tells a man, if you want to follow me, don't go home and say goodbye to your loved ones, leave the things of this world and follow me now. If you prefer the formalities of saying goodbye to your family before following me, forget it: you are not worthy of me. Strong words, strong commitment; yes, but that is the definition of Christianity. Christianity is not a vaccination you take to show others you are heaven bound; it is a lifestyle: not my will or perceptions, but your will and perceptions, Lord. Any other idea about life is wrong: You do not have in mind the things of God, but the things of men.” Jesus is telling Peter, you do not understand because you are still established in the Kingdom of men, not in the Kingdom of God. You cannot serve two masters: No one can serve two masters. Either he will hate the one and love the other, or he will be devoted to the one and despise the other. You cannot serve both God and Money. (Matthew 6:24) Money illustrates the things of this world. You cannot serve this world and fully commit to God. You cannot live for your self-interests or the interests of others and serve God wholeheartedly. When we try, we will hear the Lord say, “Get behind me, Satan!" “You do not have in mind the things of God, but the things of men.”