Sermon for August 23, 2026, Thirteenth Sunday after Pentecost

Matthew 16:13-20 (Thirteenth Sunday after Pentecost/Proper 16—Series A)

“Built on the Rock Who is Christ”

Lutheran Church of Our Redeemer, Enfield, CT

August 23, 2026

Grace, mercy, and peace to you from God our Father and from our Lord and Savior Jesus Christ. Amen.

Our text for today is the Gospel lesson recorded in Matthew 16:

¹³Now when Jesus came into the region of Caesarea-Philippi He began to ask His disciples, saying, “Who do the people say that the Son of Man is?” ¹⁴And they said, “Some John the Baptist, and others Elijah, and others Jeremiah or one of the prophets.” ¹⁵He said to them, “But you, who do you say I am?” ¹⁶And Simon Peter answered and said, “You are the Christ, the Son of the living God.” ¹⁷And Jesus answered and said to him, “Blessed are you, Simon Bar-Jonah, for flesh and blood have not revealed this to you, but My Father who is in heaven. ¹⁸And now I say to you that you are Peter, and upon this rock I will build My church and the gates of hades will not overpower her. ¹⁹I will give to you the keys of the reign of heaven, and whatever you bind on earth will stand bound in heaven, and whatever you loose on earth will stand loosed in heaven.” ²⁰Then He strictly charged them that they should tell no one that He is the Christ.

           They finally got it right! After 15+ chapters of Matthew’s Gospel, Jesus’ disciples correctly identify Jesus, the Son of Man. As was typical, Simon Peter spoke for the Twelve. “Who do you say that I am?” Jesus asked. Simon Peter replied, “You are the Christ, the Son of the living God.” Bingo! Right on the money! Jesus rightly praises Simon for the good confession of faith, “Blessed are you!” Then Jesus gives Simon a nickname, a new name, “You are Peter, and upon this rock I will build my church and the gates of hades will not overpower her.” It’s a word play. “Peter” means rock or boulder. But what did Jesus mean when He said, “You are Peter, and on this rock I will build my church”?

          One possibility is that Simon Peter himself is the rock on which Jesus would build His church. We read this in the Catechism of the Catholic Church, “Simon Peter holds the first place in the college of the Twelve; Jesus entrusted a unique mission to him. Through a revelation from the Father, Peter had confessed: ‘You are the Christ, the Son of the living God.’ Our Lord then declared to him: ‘You are Peter, and on this rock I will build my Church, and the gates of Hades will not prevail against it.’ Christ, the ‘living Stone’, thus assures his Church, built on Peter, of victory over the powers of death. Because of the faith he confessed Peter will remain the unshakable rock of the Church. His mission will be to keep this faith from every lapse and to strengthen his brothers in it” (emphasis added, par. 552).

          But there is a problem with making Peter “this rock.” First of all, the word for Peter again means “rock or boulder.” The word for rock means “a rocky ledge or cliff, a rocky peak or ridge.” Again, it is a play on words. Peter is a single boulder as opposed to a “rock ledge, a mass of living rock.” Jesus uses two different words for His word play. There is a distinction between “Peter” and “this rock.” 

          But let’s make it even simpler. If Jesus meant to say that Peter is the rock on which the whole Church was to be built, isn’t it likely that He would have simply said so? It would have been easier to say, “You are Peter, and upon you I will build my church” or “You are Peter/Rock, and upon this Peter/Rock (using the same word) I will build my church.” But Jesus doesn’t say either. He switches from Peter/Rock to “this rock ledge.” Jesus prevents a simple and automatic conclusion that Simon the man is the foundation for the Church that Jesus will build.

          Let’s take a look at it from a different angle. Is Simon Peter the rock on which Jesus will build His church? Peter’s track record is rockier and more unstable than rock-ledge firm. One commentator wrote, “Peter is not idealized as a disciple. The fifteen incidents in the Gospel [of Matthew] that specifically involve him portray him as rash, confused, desirous of reward, overconfident, faltering, and cowardly—in other words, he is a normal disciple. He is, nevertheless, unique as the spokesman for the disciples. . . . The answers of others about who Jesus is offer [Jesus] nothing on which to build. Peter’s confession does.”[1]

          So perhaps it is Simon Peter’s faith upon which Jesus will build His Church. Maybe it is Simon Peter’s faith that is “this rock.” But that is also too flimsy. How can the Church rest on a quality found in Peter and in others like him, including you and me? How can the Church of the Son of the Living God be built upon something subjective, something that could change when the wind of opinion blows in a different direction? No, the foundation of the Church is something objective, never changing, found in God’s revelation of His Word.

          That is then where we will find the answer to our problem—in the Word of Scripture. What did Jesus mean when He said, “You are Peter, and on this rock I will build my church”? This rock is not Simon Peter. This rock is not Simon Peter’s confession of faith. This rock is the content, the foundation, the very thing Peter and his faith are built on—Jesus, the Christ, the Son of the Living God!

          Jesus is not only the builder of His Church but also this rock upon which He builds His Church. He is the foundation, the Rock, upon which He will build Peter, the apostles, and all of His disciples, including you and me! Simon Peter declared what God’s Word had revealed to him, namely that Jesus is the promised Messiah, the very Son of God who became flesh and dwelt among us. Jesus told Simon Peter, “Flesh and blood has not revealed this to you, but my Father who is in heaven.” It was not Peter’s superior wisdom or knowledge that figured out Jesus’ identity. It wasn’t from human stories or ideas of philosophy. It was God the Father in heaven revealing to Simon Peter His Word through the very Word of God in the flesh and blood God-Man, Jesus.

          Through Jesus’ preaching, teaching, and healing ministry, God the Father, through the power of the Holy Spirit, was revealing His Word Incarnate to people. Jesus was proclaiming, “The reign of heaven has drawn near. It’s here now because I am here—God’s Son, the Messiah-Savior! I will show you the Father. I will give you forgiveness and life by giving up My life into death on a cross. I will give My flesh to be beaten and pierced. I will shed My blood to cleanse you forever from sin and to rescue you from God’s wrath. I will rise again on the third day becoming the Victor over death and Satan. And I will build you into My Church, My people, the people of God who trust in Me through faith as Savior and Lord.” 

The foundation of the Church, the rock of the Christian, is Jesus Christ Himself. 1 Corinthians 3:11 tells us, “For no one can lay a foundation other than that which is laid, which is Jesus Christ.” We read in Ephesians 2, “But now in Christ Jesus you who once were far off have been brought near by the blood of Christ. For he himself is our peace, … And he came and preached peace to you who were far off and peace to those who were near. For through him we both have access in one Spirit to the Father. So then you are no longer strangers and aliens, but you are fellow citizens with the saints and members of the household of God, built on the foundation of the apostles and prophets, Christ Jesus himself being the cornerstone, in whom the whole structure, being joined together, grows into a holy temple in the Lord. In him you also are being built together into a dwelling place for God by the Spirit” (Ephesians 2:13-22 ESV). And Peter himself tells us in his first letter, “You yourselves like living stones are being built up as a spiritual house, to be a holy priesthood, to offer spiritual sacrifices acceptable to God through Jesus Christ. (1Peter 2:5 ESV).

          Peter doesn’t claim to be the rock upon which the Church, the people of God with faith in Jesus Christ as Lord and Savior, is built. He knows that Jesus is this rock upon whom Peter himself, St. Paul, you, and me are built like living stones, living rocks, into a holy temple for God Himself to dwell among us with His Holy Spirit. Peter knows this because of the Word of God, because of Jesus Himself who taught the Word to Peter, to the rest of the apostles, and to us.

What kind of confidence would Peter have had facing execution by the Romans if the Church was built on him? What kind of foundation would the Church have if our faith was built on a mere man, someone with all our fears, confusions, desires, faltering, and sins? Certainly, the gates of death and the grave would easily beat us down and overcome us if we, as the people of God, were built on such an un-solid foundation. But the gates of hades cannot and will not ever rise against the people of God in Christ Jesus because Jesus has built us on Himself!

          Jesus is the Rock upon which we were built through the waters of Holy Baptism. Jesus is the Rock upon which we are built when we read and hear the Good News that Jesus is the Christ, the Son of the Living God, our Savior from sin, death, and Satan. You and I, like Peter, are built on Jesus. When we face persecution, hardship, distress, fear, economic uncertainty, medical issues, and all the many messes of life, we have a Rock foundation for our faith and for our lives that cannot be shaken. And that rock isn’t Peter, nor is it you or me—it’s Jesus Christ.

How do we know? God the Father has revealed this fact to us in His Word. It’s objective truth, always true, never to fail us. And that is why God’s Word in Romans 8 is true—always: “If God is for us, who can be against us? He who did not spare his own Son but gave him up for us all, how will he not also with him graciously give us all things? . . .  Who shall separate us from the love of Christ? Shall tribulation, or distress, or persecution, or famine, or nakedness, or danger, or sword? . . . No, in all these things we are more than conquerors through him who loved us. For I am sure that neither death nor life, nor angels nor rulers, nor things present nor things to come, nor powers, nor height nor depth, nor anything else in all creation, will be able to separate us from the love of God in Christ Jesus our Lord” (Romans 8:31-39 ESV).

We are sure. We are certain because Jesus Christ is our Rock forever. Amen.

[1] Gibbs, Matthew 11:2-20:34, Concordia Commentary, note 36, page 818.