Few verses have caused more controversy than Matthew 16:18, where Jesus says, “And I tell you, you are Peter, and on this rock I will build my church, and the gates of hell shall not prevail against it.” It has led to disagreement over the proper type of church government, the role of the pope (along with papal infallibility), apostolic succession, and more.

In context, Jesus probes his disciples for what the general public thinks about the identity of “the Son of Man” (v. 13). Their response indicates the breadth of the popular understanding of Jesus: he is John the Baptist, Elijah, Jeremiah, or another prophet (v. 14). So Jesus redirects his probe: “But who do you [plural = the disciples] say I am?” (v. 15). Peter responds for the Twelve: Jesus is the long-awaited Messiah, God the Son incarnate (v. 16). Jesus approves Peter for rightly identifying him, underscoring that his disciple didn’t humanly figure out this truth. Rather, it came as divine revelation—from Jesus’s heavenly Father (v. 17). Using a play on words, Jesus renames his disciple Peter (Greek petros) and promises to found Messiah’s church on “this rock” (Greek petra).

So what does “this rock” refer to? Let’s look at a few wrong answers before turning to what I think is the right one.

Rock as Peter and His Roman Successors

The Roman Catholic Church interprets “this rock” in reference to Peter as the first pope and the beginning of apostolic succession: Jesus authoritatively instituted an unbroken line of successors from Peter and the other apostles to the current bishops of the Roman Catholic Church. In this view, Pope Francis is now the vicar (or earthly representative) of Christ who, together with the other bishops, exercises Christ’s authority in teaching, ruling, and sanctifying the Church.

Using a play on words, Jesus renames his disciple Peter (Greek petros) and promises to found Messiah’s church on ‘this rock’ (Greek petra).

This interpretation arose centuries after the event and the writing of Matthew’s Gospel. From a Roman Catholic view, this passage is like a seed that only later flowered into the Church’s interpretation. So for Roman Catholics, the lack of mention of successors to Peter, bishops, and a hierarchical ecclesial structure—along with Jesus’s later giving of the keys not to Peter but to the church (Matt. 18:15–20)—is no deterrent to this understanding.

Additionally, the Magisterium—or teaching office of the Catholic Church—claims to possess Christ’s authority to provide the official interpretation of Scripture. And since they’ve officially interpreted Matthew 16:18 this way, this understanding stands as the authoritative and true one.

Historically, Protestants have rejected this interpretation of Jesus’s words. So how do Protestants interpret it?

Rock as Jesus or Peter’s Confession

One common Protestant interpretation says that whereas Peter is petros, a small stone, Jesus is petra, the rock. Thus, Jesus’s affirmation isn’t about a special role for Peter, but about Jesus himself as the cornerstone of the church (Eph. 2:20; 1 Cor. 3:11; 1 Pet. 2:5–8). But this view seems to be more about steering clear of the Roman Catholic interpretation than a plausible exegesis of the text itself.

A second popular Protestant interpretation says that “the rock” isn’t Jesus, but Peter’s confession about Jesus’s identity. But this truth is then shorn of any connection with the person of Peter: it is the confession itself, not Peter as confessor, that is emphasized as the foundation of Messiah’s church.

In this context Jesus affirms that he is the builder of his church, not its foundation.

There are two major problems with these interpretations. First, in this context Jesus affirms that he is the builder of his church, not its foundation. Indeed, he promises that he will build his church on the foundation of “this rock.” Second, these interpretations tend to drive a wedge between the person of Peter and his divinely revealed confession.

Rock as Peter By Virtue of His Confession

A better interpretation holds these two prominent textual elements together: The rock is Peter by virtue of his confession.

The main support for this view can be seen in the prominent salvation-historical role that Peter plays in the New Testament (especially the Gospels and the first half of Acts). His prominence is seen in various ways. He’s the first to announce the gospel to the Jews (Acts 2:14–41). Together with John, he confirms the inclusion of the Samaritans in the church (Acts 8:14–25). Finally, he is instrumental in the conversion of the first Gentiles (Acts 10–11).

This vivid narration in the book of Acts shows how the keys of the kingdom were used to build the church. And though all the apostles were active (cf. Matt. 18:18), Peter’s prominence at various key points is unmistakable.

Matthew’s Gospel certainly situates Peter among the Twelve. . . . But a proper interpretation of Jesus’s affirmation should appreciate the privilege enjoyed by Peter among the disciples.

Matthew’s Gospel certainly situates Peter among the Twelve (like them, he grasps something of the import of Jesus and his ministry while also misunderstanding a great deal). But a proper interpretation of Jesus’s affirmation should appreciate the privilege enjoyed by Peter among the disciples. He can be a spokesman for and a leader among the Twelve. And so he is, as Jesus singles him out for commendation (and renames him!) because of his confession.

Building the Church

Accordingly, “this rock” is indeed Christ’s renamed disciple Peter (Gk. petros). Yet it’s Peter by virtue of his confession that leads to Christ’s promise to build his church on “this rock” (Gk. petra). And this building project uses the keys of the kingdom of heaven as the gospel is announced throughout the world.

The phrase doesn’t support the Roman Catholic interpretation that Peter is the first pope, the vicar of Christ, the infallible head of the Church that rests on apostolic succession and wields divinely conferred authority by virtue of its possessing the keys of the kingdom. Rather, “this rock” is the foundation of the church that Jesus has been building and continues to build.

As articulated by Peter, the confession of the identity of the Messiah, God the Son incarnate, is part and parcel of both the gospel message itself and also the proper appropriation of the gospel: to all who, through the Holy Spirit, confess “Jesus is Lord” (1 Cor. 12:3), the Son gives eternal salvation for the glory of God.