The following is an excerpt from The MacArthur New Testament Commentary on Matthew 16 .

And I also say to you that you are Peter, and upon this rock I will build My church; and the gates of Hades shall not overpower it. (Matthew 16:18)

In Matthew 16:18–20 Jesus points up features and characteristics of the church that He builds. First, He set forth the foundation of the Church: And I also say to you that you are Peter, and upon this rock I will build My church.

For more than fifteen hundred years the Roman Catholic church has maintained that this passage teaches the church was built on the person of Peter, who became the first pope and bishop of Rome and from whom the Catholic papacy has since descended. Because of this supposed divinely ordained apostolic succession, the pope is considered to be the supreme and authoritative representative of Christ on earth. When a pope speaks ex cathedra, that is, in his official capacity as head of the church, he is said to speak with divine authority equal to that of God in Scripture.

Such an interpretation, however, is presumptuous and unbiblical, because the rest of the New Testament makes abundantly clear that Christ alone is the foundation and only head of His church.

Peter is from petros, a masculine form of the Greek word for small stone, whereas rock is from petra, a different form of the same basic word, referring to a rocky mountain or peak. Perhaps the most popular interpretation is therefore that Jesus was comparing Peter, a small stone, to the great mountainous rock on which He would build His church. The antecedent of rock is taken to be Peter’s divinely inspired confession of Jesus as “the Christ, the Son of the living God” (vv. 16–17).

That interpretation is faithful to the Greek text and has much to commend it, but it seems more likely that, in light of other New Testament passages, that was not Jesus’ point. In his letter to Ephesus Paul says that God’s household is “built upon the foundation of the apostles and prophets, Christ Jesus Himself being the corner stone” (Eph. 2:20). In all four gospel accounts Peter is clearly the leading apostle, and he remains so through Acts 10. He was most often the Twelve’s spokesman during Jesus’ earthly ministry (see, e.g., Matt. 15:15; 19:27; John 6:68), and he was the chief preacher, leader, and worker of miracles in the early years of the church (see, e.g., Acts 1:15–22; 2:14–40; 3:4–6, 12–26; 5:3–10, 15, 29).

It therefore seems that in the present passage Jesus addressed Peter as representative of the Twelve. In light of that interpretation, the use of the two different forms of the Greek for rock would be explained by the masculine petros being used of Peter as an individual man and petra being used of him as the representative of the larger group.

It was not on the apostles themselves, much less on Peter as an individual, that Christ built His church, but on the apostles as His uniquely appointed, endowed, and inspired teachers of the gospel. The early church did not give homage to the apostles as persons, or to their office or titles, but to their doctrine, “continually devoting themselves to the apostles’ teaching” (Acts 2:42). When the Jews outside the Temple were astonished at the healing of the crippled man, Peter quickly warned them not to credit him with the miracle, saying, “Men of Israel, why do you marvel at this, or why do you gaze at us, as if by our own power or piety we had made him walk?” (Acts 3:12). Although it was he alone who commanded the man to walk (v. 6), Peter replied to the crowd in John’s behalf as well as his own.

Because they participated with the apostles in proclaiming the authoritative gospel of Jesus Christ, the prophets of the early church were also part of the church’s foundation (Eph. 2:20). In fact, as Martin Luther observed, “All who agree with the confession of Peter [in Matt. 16:16] are Peters themselves setting a sure foundation.” The Lord is still building His church with “living stones … built up as a spiritual house for a holy priesthood, to offer up spiritual sacrifices acceptable to God through Jesus Christ” (1 Pet. 2:5).

Therefore, whether one interprets Matthew 16:18 as referring to Peter as a small stone placed on the mountainous stone of his confession of Christ or as referring to his being one with the rest of the Twelve in his confession, the basic truth is the same: The foundation of the church is the revelation of God given through His apostles, and the Lord of the church is the cornerstone of that foundation. Because it is His Word that the apostles taught and that the faithful church has always taught, Jesus Christ Himself is the true foundation, the living Word to whom the written Word bears witness (John 5:39). And “No man,” Paul says-not even an apostle-“can lay a foundation other than the one which is laid, which is Jesus Christ” (1 Cor. 3:11). The Lord builds the church on the truth of Himself, and because His people are inseparable from Him they are inseparable from His truth. And because the apostles were endowed with His truth in a unique way, by their preaching of that truth they were the foundation of His church in a unique way.

Although Peter recognized himself as an apostle (see, e.g., 1 Pet. 1:1; 2 Pet. 1:1), he never claimed a superior title, rank, or privilege over the other apostles. He even referred to himself as a “fellow elder” (1 Pet. 5:1) and as “a bond-servant” of Christ (2 Pet. 1:1). Far from claiming honor and homage for himself, he soberly warns his fellow elders to guard against lording it over those under their pastoral care (1 Pet. 5:3). The only glory he claimed for himself was that which is shared by all believers and which is yet “to be revealed, … when the Chief Shepherd appears” (vv. 1, 4).