In Matthew 16:18, Jesus tells Simon, “You are Peter, and on this rock I will build my Church.” Catholics interpret the rock as a reference to Peter. From this, Catholics infer that Jesus intended Peter to be the visible foundation and head of his Church on earth. This makes Peter the source of unity for Christ’s Church—for, wherever the foundation and head is, there is the true Church of Jesus.
Catholics appeal to this verse as biblical evidence for the papacy because the Catholic doctrine of the papacy is precisely that Christ appointed Peter and his successors to be the source of unity of and the identifying mark for Jesus’ Church on earth.
Some Protestants reply by conceding that Peter is the rock but challenge the idea that he is unique in being the foundation of the Church. Let’s look at two such replies.
1. “All the apostles are the foundation, not just Peter”
One argument appeals to Ephesians 2:20, where Paul teaches the “household of God” is “built upon the foundation of the apostles and prophets, Christ Jesus himself being the cornerstone.” Well-known Protestant apologists Norman Geisler and Ralph MacKenzie write of this passage: “Two things are clear from this: all the apostles—not just Peter—are the foundation of the church . . . and the only one who was given a place of uniqueness or prominence was Christ, the capstone” (208).
Geisler and MacKenzie seem to be making two arguments here. First, since the apostles too are identified as the foundation of the Church, there’s nothing unique about Peter being the rock of the Church in Matthew 16:18. The second argument is that if Peter were unique as the foundation of the Church, then he would have been distinguished from the other apostolic foundation stones, as Jesus is distinguished. But since he’s not, Geisler and MacKenzie conclude that Peter is not unique.
In response to the first argument, there’s an assumed hidden premise that Geisler and MacKenzie never say out loud: whenever something is said of two people, those two people must be equals with regard to what is said about them. Only if this premise is true can Geisler and MacKenzie conclude that Peter has no unique status relative to the apostles based on the fact that the “foundation” metaphor is used for both Peter and the apostles.
The problem for Geisler and MacKenzie is that this hidden premise is demonstrably false. Consider, for example, how Jesus is called our shepherd in 1 Peter 2:25: “For you were straying like sheep, but have now returned to the shepherd [Greek, poimena] and Guardian [episkopon] of your souls.” This Greek word for shepherd, poimena, is also used to describe pastors in the Church—for example, where Paul writes, “And his gifts were that some should be apostles, some prophets, some evangelists, some pastors [Greek, poimenas] and teachers” (Eph. 4:11). If we were to follow Geisler and MacKenzie’s logic, we’d have to conclude that Jesus has no unique status as our pastor, since the Bible says there are other pastors in the Church, too!
Now let’s consider the second argument: if Peter were unique as the foundation of the Church, then Paul would have singled Peter out among the other apostles as he did for Jesus. Since Paul didn’t do such a thing, Peter must have no special role as the foundation of the Church.
But why must we think that Paul would have singled Peter out among the apostles the way he did for Jesus? It’s reasonable to think that only if Paul’s focus were Peter and his role as the rock of the Church in relation to the other apostles. But that is not Paul’s focus.
Paul’s focus is on the Ephesians and their relation to the apostles and Jesus as pieces that make up the edifice of the Church, which Paul calls a “holy temple” (v. 21). The Ephesians are pieces built into the edifice. The apostles and prophets are the foundation. And Jesus is the cornerstone, “in whom the whole structure [of the Church] is joined together” (v. 22).
Since Paul’s concern is not the order among the apostles as the foundation of the Church, but simply the order that exists among the Ephesians, the apostles and prophets, and Jesus as pieces that make up the edifice of the Church, we shouldn’t expect Paul to highlight Peter’s unique status as the rock of the Church.
The “foundation” metaphor is being used in Ephesians 2:20 in a different context and for a different purpose. We must read it accordingly and not try to shoehorn its meaning into an entirely different context, such as that of Matthew 16:18. The reverse is true as well. We shouldn’t take the Catholic interpretation of Peter as the rock in Matthew 16:18 and force its meaning onto Ephesians 2:20. We have to remember that metaphors can be used in more than one way in the Bible.
2. “Peter is only a pillar, not the pillar”
Another Protestant counter derives from Galatians 2:9, where Paul writes, “When they perceived the grace that was given to me, James and Cephas and John, who were reputed to be pillars, gave to me and Barnabas the right hand of fellowship.” That Peter (called Cephas, the Greek transliteration of the Greicized Aramaic Kephas) is named second in this list of pillars is taken as proof that Peter is not unique in his role as the foundation of the Church. Protestant apologist Jason Engwer makes the argument this way:
It’s doubtful that people would have been grouping Peter with other apostles as pillars of the church and naming him second, after James, if he was thought of as a pope. Remember, Catholics are the ones who place so much emphasis on the alleged significance of Peter’s being a foundation of the church in Matthew 16, which is similar to the pillar concept in Galatians 2:9. It’s highly unlikely that the early Christians believed that Peter was such a unique foundation of the church, the infallible ruler of all Christians, including the other apostles, yet perceived him as described in Galatians 2:9.
We might summarize this argument as follows:
Premise 1: If Peter were unique as the foundation of the Church according to Matthew 16:18, then he would not have been listed second as a pillar of the Church in Galatians 2:9.
Premise 2: Peter is listed second as a pillar of the Church in Galatians 2:9.
Conclusion: Therefore, Peter is not unique as the foundation of the Church according to Matthew 16:18.
The underlying assumption of premise one is that being listed second must reveal an inferior rank. But we can challenge this assumption, for there are additional plausible explanations for Peter being listed after James.
The order of the list, with James first, Peter second, and John third, may simply be a consequence of the order in which these men’s names came into Paul’s mind as he was dictating. When we list people or things when writing an email or telling a story, we typically do not intentionally list them in order of importance or greatness unless we have a reason to—and so, without any indication of such a reason in this text, there’s no cause to think that Paul is doing so here.
Even if Paul did intend some significance to the ordering, it still does not require the conclusion that Peter did not have the special role that Catholics say he was given in Matthew 16:18.
First, because elsewhere in Galatians, Peter seems to be ranked above James. Evidence suggests that this James (not the brother of John—the other one) became the leader of the Jerusalem church when Peter left after his imprisonment (Acts 12:17). Recall Galatians 1:18-19, where Paul speaks of his first trip to Jerusalem shortly after his conversion and implies that Peter’s in charge. He writes, “Then after three years I went up to Jerusalem to visit Cephas, and remained with him fifteen days. But I saw none of the other apostles except James the Lord’s brother.” So it would be a mistake to portray Galatians as if it uniformly supported James holding rank over Peter. The first chapter of the letter does the reverse.
So what is happening in Galatians 2:9? This trip takes place fourteen years after Paul’s initial visit with Peter (see Gal. 2:1), who had left Jerusalem and gone to Antioch after he escaped from prison. Peter’s absence from Jerusalem would have given James the opportunity to take the reins to oversee the Jerusalem church (cf. Acts 21:17-24). Protestant New Testament scholar F.F. Bruce explains:
On Paul’s earlier visit to Jerusalem, Cephas was the most important man in the church; Paul went up specifically to meet him, and adds that he also saw James. But all our evidence (scanty as it is) indicates that James became increasingly influential in the Jerusalem church. An opportunity to increase his influence at the expense of Cephas/Peter came with the latter’s departure from Jerusalem after his escape from Herod Agrippa’s prison (121-122).
That James had become the bishop of the Jerusalem church at the time Paul visits Jerusalem in Galatians 2:9 provides a plausible explanation as to why Paul might have intentionally listed James first. It could have been a way of acknowledging his current headship in the local church. Peter was only there temporarily to attend the Council of Jerusalem.
There is yet another plausible explanation: Paul was undercutting the claims of the Judaizers. These were a group of first-century Jewish Christians who argued that Gentiles needed to be circumcised if they wanted to be Christian. Paul called them the “circumcision party” in Galatians 2:12, and they held James in high esteem. In fact, in that same verse, Paul tells us that the Judaizers, whom Peter feared offending, “came from James.” So, if there were anyone that the Judaizers would have tried to pit against Paul concerning whether the Gentiles should be circumcised, it would have been James.
Paul counters this move by showing that James endorsed his view that circumcision is unnecessary for the Gentiles. And perhaps to drive home the point, Paul lists James first as a pillar: “When they perceived the grace that was given to me, James and Cephas and John, who were reputed to be pillars, gave to me and Barnabas the right hand of fellowship” (Gal. 2:9). Paul thereby undercut any attempt by the Judaizers to make their case by appealing to official backing from the Jerusalem church.
These are just two of many Protestant comebacks to Catholics’ reliance on Matthew 16:18 to defend the papacy. But no matter where the discussion might go, Catholics can be confident that Peter is indeed the rock on which Christ’s church is built.