Luke 9:18-27 Jesus & Peter and the cost of discipleship

Luke 9:18-27 Jesus asks the disciples who He is and Peter says He is the Christ. Parallel passages in Matthew 16:13-20 and Mark 8:27-33.  The reporting on the first part is very consistent. Jesus first asks the disciples who the multitude thinks He is, and then He asks them who they think He is, evoking Peter's response 'Thou art the Christ, the Son of the Living God.' (Matt 16:16). But the discussion after this apparently went in a number of directions, with two different reports in different gospels.

         Matthew records the part of the conversation where Jesus blessed Peter because he had just received a revelation from the Father in heaven, and that He is going to build His church on the rock and thee gates of hell will not overpower it; and furthermore He will give Peter the keys of the kingdom of heaven, and authority to bind and to loose both on earth and in heaven. There might be some question about what Jesus was referring back to when He said He would build His church upon this rock. Some believe He was referring to Peter, to whom He had given the name petros, the Greek word for stone. Some believe He was referring to the act of confessing Jesus as the Christ, the Son of God, the foundational belief for conversion and salvation. Another possibility is that He was referring to the act of hearing the Father's voice and declaring it, which is the basis for doing His will.

         Mark and Luke record that Jesus then began to talk about His upcoming suffering and death. Peter then rebuked Him, and Jesus then rebuked Peter and Satan, for setting his mind on man's interests rather than God's. He followed this up with a warning to the disciples that whoever wants to follow Jesus must take up his own cross, and that whoever wishes to save his life shall lose it, what does it profit a man to gain the whole world and lose his soul? For whoever is ashamed of Jesus now, He will be ashamed of him when He comes in the glory of the Father.

         Why would these two different aspects of the consequences of Peter's declaration be reported independently? Eschewing discussion of the intended audience for each of the gospels, we have a fundamentally different take on what it means to confess Jesus as the Christ, the Son of God. Matthew records the authority that comes through Christ, while Mark & Luke record the cost of following Him. Most likely both were part of the conversation that ensued after Peter's declaration. We don't know the order, but that is unimportant. What we must not miss is that Jesus was showing them the very nature of God in His own life - that He was God and that He was going to die to pay the price for the sin of the world. And that in a similar vein, the church was going to have authority in His name to bind and loose, the very keys to the kingdom of heaven, but that the cost of this authority will be that each believer must carry his own cross. By implication that cross is to give up the world and if necessary our physical lives but at the very least our soul-life (ownership of the priorities of our lives, finding our satisfaction in the things of this life rather than His kingdom), or else Jesus will be ashamed of us at the second coming.