DUNCAN/The necessity of the cross

Please turn in your Bibles to Matthew 16:21-23. We come to a significant point of departure in Jesus’ teaching of His disciples. He begins to explicitly, regularly, and forcefully explain to the disciples the necessity of His death in connection with who He was.  We will see three things from this passage. First, we must understand the necessity of the cross if we are to understand Christianity.  Second, we must submit our thinking to the authority of the word if we are to be Christ’s disciples.  And third, we must realize that the way to glory is the way of the cross, and beware any other suggestion.

I. We Must Understand the Necessity of the Cross if We Are to Understand Christianity

In verse 21, Christ foretells the cross.  We read, “From that time Jesus began to show His disciples that He must go to Jerusalem, and suffer many things from the elders and chief priests and scribes, and be killed, and be raised up on the third day.” We learn that you cannot understand Christianity if you don’t understand the cross. Christianity makes no sense apart from the cross.  As soon as Jesus saw that the disciples have grasped that He is both the long-expected Messiah and the very Son of God, He knew that the time had come to teach them a more unsettling aspect to the good news. Now, He must teach them that Messiah must die.  

Think first of all of where He says He’s going to suffer.  He says He must go to Jerusalem to suffer and be killed. That is a shock to the disciples because Jerusalem is very much in their minds as a center point of the hope of all the people of God.  Notice, also, who Jesus says is going to administer these sufferings.  He says to the disciples that the chief priests and the scribes and the elders are going to be the ones who administer the suffering and who ultimately kill Him.   

Why did Jesus tell the disciples this, at this time, at this glorious time when they’d made this public announcement about the fact that they had come to believe Him fully? Why at that moment would Jesus begin to teach them about His death?  First of all, it was absolutely important for Jesus to teach His disciples about His death, because His sufferings and His cross were not an accident. It was vital for His disciples to know that what was going to happen to him in the months to come was not something that He was unprepared for, it was not something that He had not planned for, in fact, it was what He was born for.  Jesus also said this word to the disciples to correct their understanding of the Messiah and of the kingdom of heaven.  The disciples were still thinking of the kingdom of heaven in earthly terms. They were still expecting an earthly rule of Christ. It was also absolutely essential for Jesus to teach the disciples this to prepare them for the sorrow and pain and turmoil that they would go through in the hours of His crucifixion and the aftermath of His death.  

Jesus had to teach the disciples the truth of His death, because it would be their job in due time, after His death, after His resurrection, after His ascension, after Pentecost, to be the prime force in proclaiming the gospel of the kingdom of heaven to the world. Jesus is saying right here that His cross is at the center of the proclamation which His disciples must proclaim, because the cross is at the center of God’s strategy of redemption, His plan of redemption. So, He begins to teach the disciples about it here.   

II. We Must Submit Our Thinking to the Authority of the Word if We Are to Be Christ’s Disciples 

We see Peter’s response in verse 22. He says, “God forbid it, Lord! This shall never happen to You.” We learn in verse 22 that we must submit our thinking to Christ if we’re going to be His disciples.  For a moment, Peter, who had just made this great confession, begins to think in the flesh.  Peter doesn’t understand the essence of the shameful death of Christ for the purposes of God.  That was going to be the way that God would purchase our salvation.  You see, Peter’s response was motivated by a misunderstanding of the nature of the kingdom. And by a misunderstanding of the nature of the Messiah.

We must understand very clearly what Jesus is saying here.  Do we understand that that cross is absolutely essential to His kingdom? Do we understand that the cross is absolutely essential to our salvation? Do we understand that the way of humiliation is God’s way of exaltation? It’s the opposite from the way the world thinks. And Jesus is beginning to teach His disciples in the true way of thinking. 

III. We Must Realize That the Way to Glory Is the Way of the Cross, and Beware Any Other Suggestion 

In verse 23, we see Jesus’ rebuke to Peter. We learn here again that the way of the cross is the way to glory, and not any other suggestion that says there is a way into fellowship with God around the cross. A suggestion that there’s a way into fellowship with God apart from the cross, that there’s a way into fellowship with God by my own good works.  There’s a way into fellowship with God in any religion because all roads lead up the same mountain. Any teaching that says there is a way into fellowship of God apart from the cross is a lie from the pit of hell. Jesus makes that clear here, because He says to Peter, the one that He had just pronounced blessed, “Get behind me, Satan!”  

Why in the world would He say that to His disciple?  Jesus heard a satanic trap being laid in Peter’s words.  Jesus’ response is swift and brutal. Why? Peter’s rebuke was based on the wisdom of the flesh. That wisdom of the flesh had to be exterminated in Peter if He was to be saved spiritually. Peter’s challenge to Jesus’ truth was at the very heart of the gospel. To deny the cross is to lose the gospel.  To lose the gospel is to lose salvation. No cross, no gospel, no salvation.  

Jesus here is teaching the absolute necessity of the cross.  He opposes anything that qualifies the absoluteness of the necessity of His saving death.  That is at the heart of the gospel. Have you embraced the absolute necessity of the cross for your salvation? If you have, you have trusted on Jesus Christ alone for your salvation, because you know that any other way is the way of death. May God help us all to practically acknowledge the truth of the centrality of the cross in the gospel. 

The Rev. Dr. J. Ligon Duncan III is Chancellor and CEO of Reformed Theological Seminary.  He can be reached at 601-923-1600 or by email at jhyde@rts.edu.