The Rock
Original sermon given on The Thirteenth Sunday after Pentecost, August 23, 2026 written and delivered by Pastor Jeff Leininger at First Saint Paul’s Lutheran Church.
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“The Rock”
Matthew 16.13-20
The Rock
In the name of the Living God and the Risen Christ. Amen.
If you’re going to build right, you’ve got to start right. How and where you begin matters. This is obviously true with architecture, construction, and engineering. If you go into our lounge, across from the wooden Angel which survived the Great Chicago Fire, you’ll see some photos on the wall. One of them is a picture of the cornerstone of this building being laid in 1969. And while it’s no doubt true that some of the Lutherans in this congregation likely “talked about how much they liked the old building” this “new” one has certainly survived the test of over half a century.
How and where you start matters. It’s equally true in business. What are the founding principles of the company you work for? Have they shifted over the years? Or in Education: our neighbors down the street at Moody Bible Institute in August welcomed Dr. Rick Melson to serve as eleventh President. Although a man of great prayer and faith, I can assure you that he no doubt will be examining closely the foundations of a school which has proclaimed Christ since 1886, but which now operates in a very difficult period for higher education across the country. How and where you start matters.
Families too have to build right from the start. When I meet with families about baptism or with young couples about marriage, I will always speak about the importance of solid foundations. What do you want to be the center of your marriage or family?
Jesus begins building something here in Matthew 16. He lays a cornerstone. And he’s got to start right and build upon the most solid foundation, for what he builds is to last for eternity.
But our Lord’s construction project is unlike anything that has ever been made or will ever come after it. There are a number of surprising, almost shocking twists we find in today’s gospel. Who builds like this?
First, where he builds. Jesus and his disciples have traveled north of Galilee about 25 miles — a day’s journey by foot. And they have entered into the pagan, Greek region of Caesarea Phillippi. Around 2 BC, the son of King Herod the Great, Philip, expanded, refurbished and renamed the city after himself (Philippi) and Caesar Augustus (thus Caesarea-Philippi). It’s a beautiful, lush, and green area even today, as the headwaters of the Jordan flow down from Mt. Hermon nourishing the area. We don’t know for sure if Jesus actually went into the city itself (Mark’s gospel mentions “the surrounding villages”), but if he did, he and his followers would have been confronted by some of the worst examples of Greek paganism in that part of the world.
This was the city of the god Pan, the half-man half-goat god who supposedly came out of the gates of Hades here. You can still go and see the ruins of Pan’s temple; his grotto (he had a temple and grotto — that’s living life, right!?); the Court of Pan and the Nymphs; the Temple of Pan and the Sacred Goats; the Temple of Pan and the Dancing Goats; as well as numerous other pagan temples dedicated, for example, to Augustus (the Son of god) and to Zeus (king of the gods).
I paint this picture to help us understand the remarkable where of Jesus’ construction project. He’s a Jewish Rabbi, surrounded by Jewish fisherman, who give him very Jewish answers to the question, “Who do people say that the Son of Man is?” — “…some say John the Baptist, others say Elijah, and others Jeremiah or one of the prophets.” (Matt. 16.13,14)
But the answer to the question, “What about you, who do you say I am?” — “The Christ (Messiah), son of the Living God” — this answer will resound all over the world. The cornerstone laid near Caesarea Philippi will overthrow all the pagan gods with the worship of the one, true God revealed in Jesus Christ. Jews and Gentiles both will be united by the death and resurrection of Jesus, Messiah. His cross forgiving all sin and his resurrection defeating death for all. St. Paul writes about this in Ephesians 2. Speaking about Jews and gentiles, he says:
But now in Christ Jesus you who were once far off have been brought near by the blood of Christ. For he himself is our peace, who has made us both one and has broken down in his flesh the diving wall of hostility… (Eph. 2.13-14)
Where Christ builds —in this pagan, Gentile region — is strange indeed, for his church, his ecclesia, will be an assembly of all nations and backgrounds, united in their confession of him. And the portal to the underworld will not triumph over it.
Secondly, what he lays — the cornerstone upon which he builds — is also strange. It’s not a physical object, like a literal cornerstone; nor a strategic plan; nor a 501(c)3 non-profit; nor a company; nor an army; nor a political party; nor an endowment. Christ builds upon a confession. Words. Heavenly words spoken by a human being. The acknowledgment of who Jesus is.
These words are not of human origin, but divine. When the question is turned personal: “You (plural), who do you say I am,” Peter responds with, “You are the Christ (Messiah), son of the Living God.” Jesus commends him on this confession and even gives him a new name, Peter (Petros), little rock. But what Jesus builds his church upon is not the person, Petros (little rock), but rather the Petra (big rock) —- that is, the confession of who Jesus is as Messiah and Son of God. “And I tell you, that you are Peter, and on this rock (Petra) I will build my church.” (Matt 16.18)
The church is built upon this foundation stone — words and hearts and minds professing who Jesus is and what he has done. As St. Paul writes in Romans 10:
…if you confess with your mouth that Jesus is Lord and believe in your heart that God raised him from the dead, you will be saved. For with the heart one believes and is justified, and with the mouth one confesses and is saved. (Romans 10.9-10)
It is this confession of who Jesus is that will never be overcome, even if Zeus or Pan (and all his goats) or all hordes of hell itself would pour out against it. And it is this same confession of Christ that we also stand upon and build upon.
A third strange twist regarding Christ’s construction project has to do with the building materials. What is the building made of? How is his church constituted? It’s not ultimately of brick or wood or stone or cement. It is built of people: the baptized, brought into the life, death, and resurrection of Christ, who confess together his saving name. Filled with his Spirit, we become the holy habitation where the Lord’s work is done and where he dwells. Peter himself speaks of it this way, in his first Epistle:
As you come to him, a living stone rejected by men but in the sight of God chosen and precious, you yourselves like living stones are being built up as a spiritual house, to be a holy priesthood… (1 Peter 2.4-5)
Living, breathing, witnessing, praising, giving, serving, loving, confessing stones — what a strange building, indeed, made up of flesh and blood filled with the Spirit! And because it is built of living stones upon the one living stone, Jesus Christ, this building of bodies (the church) has spread now all over the world. Wherever his name is confessed and his work proclaimed and his baptized people gather around his body and blood, there you have his church/assembly. In storefronts, in cathedrals, in catacombs, in foxholes, on farms, in cities, in huts, in homes, on streets, from Chicago to Tanzania to Antarctica, we are the living stones of the Living One.
The fourth and last surprising twist regarding what Christ has come to build, is how long it lasts. Its endurance. St. Peter (little rock, Petros) didn’t fully understand that the confession he made (big rock, Petra) that day near Caesarea Philippi would have eternal significance. You see, everything we build will one day fall. Every worldly foundation cracks. Every wall erected crumbles. Every dollar earned, saved, and invested becomes worthless. Every army will be defeated, human agenda thwarted, king dethroned, tribe scattered, nation undone. But not this one. The one built right, started right, by Jesus himself upon the confession of who he is — this one lasts forever.
St. John in the book of Revelation (the Apocalypse) saw it better than we. He saw the same church/ecclesia, begun with Peter’s confession at Caesarea Philippi — begun in the shadow of the gates of hell — but now shining in the halls of eternity. From Revelation 7:
After this I looked, and behold, a great multitude that no one could number, from every nation, from all tribes and peoples and languages, standing before the throne and before the Lamb, clothed in white robes, with palm branches in their hands, 10 and crying out with a loud voice, “Salvation belongs to our God who sits on the throne, and to the Lamb!
If you’re going to build right, you’ve got to start right. How and where you begin matters. Who do you say he is? The confession of Jesus as Messiah begins in the strangest places, has the strangest foundation (words), is made up of the strangest things (people), but lasts unto eternity.
Come soon Lord Jesus. Amen.
Image Source: Raphael, 1483-1520. Christ's Charge to Peter, from Art in the Christian Tradition, a project of the Vanderbilt University Divinity Library, Nashville, TN. https://act.library.vanderbilt.edu/artworks/55924 [retrieved August 24, 2026]. Original source: http://www.vam.ac.uk/content/articles/t/raphael-cartoons/.
