Matthew 16 has some pretty wonderful content if you are the Apostle Peter, but it also contains what looks like a mistake of judgment on the part of Jesus.
Jesus said to Peter, "You are Peter, the rock, and on this rock, I will build my Church, and the gates of hell won't overpower it. I will give you the keys to the kingdom of heaven. Whatever you tie up on earth will be tied up in heaven, and whatever you untie on earth will be untied in heaven." Matthew 16:18-19
What beautiful promises from Jesus! What a high and noble calling for Peter!
Yet, in the next breath, Jesus related to His disciples His plan and prediction for the near future. Jesus' ideas didn't sit well with Peter, the rock, the one on whom Jesus would build His Church, and Peter ardently opposed Jesus' plan, believing it to be a dangerous mistake. How does Jesus respond to His general's advice? By calling him 'Satan'!
Jesus turned on Peter. "Get behind me, Satan! You are trying to trip me up! You are not looking at things like God does! You are looking at things like a mere mortal!" (Matthew 16:23)
What is this about? Is Jesus rescinding His blessing on Peter? Is Jesus regretting the commission He gave? Did Jesus speak too soon in promoting Peter?
Of course, we all know the answer: Jesus didn't make a mistake because Jesus doesn't make mistakes, which should lead us to two other important conclusions:
First, well-meaning Christians, who have an anointing from God and deep loyalty, can still be used by Satan. Sometimes we live with fears, insecurities, wounds, and lies for so long, that we cannot recognize when they are at play and wreaking havoc in our lives and the lives of others. Our bad habits of the heart and mind may appear "normal" to us, even while they are refuges for lies of the enemy. Good Christians can still make bad mistakes.
Secondly, the fact that we fail does not disqualify us from our noble calling. Jesus knew Peter had problems, He knew that Peter would make mistakes, and He still promised to build His Church upon him! It is because Jesus still planned to build His Church on Peter that Jesus had to rebuke him. Later, Peter would describe the Church as a building of "living stones" (1 Peter 2:-5). The stones of God's building must be chiseled into shape to function properly in the wall of God's city. Discipline is a necessary companion of a Holy calling.