IN the last verses in this chapter the Messiah-ship of Jesus and his deity has been established through Peter's confession, and the words of Jesus that on this confession that Jesus is the Christ, the Son of the living God, Jesus would build his church. Now that this truth has been established Jesus can go on to further teaching about himself and God's purpose for him through his incarnation. So we find Jesus commencing this teaching here, which he continued right up to the time it was fulfilled in his death and resurrection.

This further teaching is that Jesus must suffer many things at the hands of the Jewish authorities, who will then kill him, but he would rise to life again. This beginning of this further important teaching is indicated in the opening of verse 21 - “From that time on Jesus began to explain...”. Jesus had to make sure that his Messiah-ship and deity were first established and understood before he could go on to explain that he must die. The importance of the death of Jesus is in the fact that it was the incarnate Son of God who died. It is the fact of who Jesus was that made his death so significant and efficacious.

It is evident from verse 21 that this verse is only a summary of what Jesus said. He explained this summary at length, and not just at this time, but continually in the time ahead. The evidence of this repeated teaching is found in the many references to it in the Gospels – e.g. Matthew 20:28; Mark 10:45; Luke 12:50; 13:33; 22:37; 24:26; 27, 44; John 1:29 as well as in other places in the New Testament.

It is surprising that the disciples just did not take in this teaching, and when Jesus was taken by the Jews and crucified they were devastated. It would seem that all Jesus had explained was a waste of time, but this is not so, for because of the teaching, after the resurrection, the Holy Spirit was able to bring back this teaching and so establish the disciples in the marvellous truth of Christ's finished work of atonement.

We should notice how Jesus tells the disciples that he 'must' suffer and die. Although, as we shall see, Peter expressed, what all the disciples believed, that it was impossible for the Christ to die, Jesus needed to impress on them that his suffering, death and resurrection was an essential part of the work God, the Father, had given him to do. This tells us that the death of Jesus is the core of the Gospel. Jesus came to give his life a ransom for sinners, because only by this sacrifice could sinners be saved from the penalty for sin, which their sin deserves. The heart of the Gospel, and the truth concerning Jesus, is in his death. The incarnation was necessary for his death to be totally saving, but the incarnation on its own has no power to save. This is something that modern theological opinion fails to uphold, and so those who hold such opinion are like Peter here, and by their denigration of the death of Jesus, are doing Satan's work, and depriving souls of eternal life. Only by the death of Jesus as our substitute can we know eternal life.

So we come to this low point in the experience of Peter. He had reached a great high when by the Spirit he had declared that Jesus was the Christ, the Son of the Living God. Now he reached a decided low. Peter, with the tradition concerning the Messiah that he had been nurtured in, felt that it was totally inconceivable and wrong for the Messiah to suffer and die. In the understanding he had been nurtured in the Messiah would lead the Jews to great victory over their enemies. How could it be possible that the very people he was to lead to victory should be the ones to reject him and kill him.

Peter must have remonstrated with Jesus in a voice audible to all the company of the disciples who were present, and so Jesus rebukes Peter in a similar public way. It was important for all to understand that it was the will and purpose of God that Jesus should suffer and die and rise again. Only in this way could sinners be freed from the dominion of Satan, and saved from God's wrath against all sin and sinners.

Jesus tells Peter the plain truth. To oppose his suffering and death was to do the exact thing which would serve the purpose of Satan, and maintain all humanity under his rule and condemnation. Jesus plainly tells Peter that to oppose his death was to oppose God, for it was contrary to the mind of God, and was in fact expressing the mind of Satan. The death of Jesus as a ransom for sin is the heart of the Gospel, and the only means by which sin can be atoned for, and the sinner saved from the penalty of sin which is death.