WHAT KIND OF “ROCK” IS PETER?
Jack Cottrell – February 2018

QUESTION: Does Matthew 16:18 say that the Apostle Peter is the ROCK on which the church is built? Does this support the Roman Catholic teaching that Peter was the first Pope?

ANSWER: The text in question is included here, in Matthew 16:15-18: “15 He said to them, ‘But who do you say that I am?’ 16 Simon Peter answered, ‘You are the Christ, the Son of the living God.’ 17 And Jesus said to him, ‘Blessed are you, Simon Barjona, because flesh and blood did not reveal this to you, but My Father who is in heaven. 18 I also say to you that you are Peter, and upon this rock I will build My church; and the gates of Hades will not overpower it’” (NASB).

The issue of interpretation that is at stake here is seen in an online essay by a Roman Catholic writer, Karl Keating, entitled “Peter the Rock” [https://www.catholic.com/tract/peter-the-rock]. Keating describes his encounter with a Seventh-Day-Adventist missionary, who tried to convert him by attempting to disprove the way Catholics usually interpret Matthew 16:18.

In this encounter, as soon as the missionary mentioned the Matthew 16:18 text, Keating said to him, “Hold it right there! . . . That’s where Jesus appointed Simon the earthly head of the Church. That’s where he appointed him the first pope.” I.e., Simon Peter is the ROCK on which the church is built. This is how Catholics understand this text.

The missionary immediately pointed out that this is not what the Greek original says. “In Greek, the word for rock is petra, which means a large, massive stone. The word used for Simon’s new name is different; it’s Petros, which means a little stone, a pebble.”

At this point the Catholic, Keating, tries to dismantle this common argument against the Catholic view. He says petros and petra in ancient classical Greek may have had this distinction, but in first-century (NT) Greek “the words petros and petra were synonyms.” Maybe they meant “small stone” and “large rock” centuries before the time of Christ, “but that distinction had disappeared from the language by the time Matthew’s Gospel was rendered in Greek. . . . In Koine Greek, both petros and petra simply meant ‘rock.’ If Jesus had wanted to call Simon a small stone, the Greek lithos would have been used.”

Also, says Keating, we must remember that Jesus actually spoke in the Aramaic language, and Matthew’s Gospel may even have been originally written in Aramaic. And in Aramaic there was only one word for “rock,” i.e., Kepha (or Kephas, as in Cephas). So Kepha means “rock,” the same as petra. So, “what Jesus said to Simon in Matthew 16:18 was this: ‘You are Kepha, and on this kepha I will build my Church.’” Also, the only reason the Greek version uses Petros instead of petra is that the former ending (-os) is masculine in Greek while the -a ending is feminine. So it was changed to the masculine ending since Peter is male.

Therefore, says Keating, we must conclude that this is where Jesus appointed Peter as the first Pope.

How can we respond to this? Most Protestants have rejected and still do reject this line of reasoning, for several reasons.

First, the argument from the Aramaic language makes too little of the fact that the only version of Matthew that we have and of which we can be sure is the Greek. Jesus probably did speak Aramaic, but how he would have worded this statement to Peter in Aramaic is pure speculation. As R. C. H. Lenski says, we must “challenge the reference to the Aramaic in order to wipe out the distinction between petros and petra. We know too little about the Aramaic to assert that when Jesus spoke these words he used the same Aramaic term in both statements” (The Interpretation of St. Matthew’s Gospel, Augsburg 1993, 627).

As with all other NT books, we must conclude that the original was written in Greek, and that Matthew was inspired by the Holy Spirit as he wrote. Thus, whatever Aramaic terms Jesus may have used in his conversation with Peter, we know via the Holy Spirit that the intended connotations were Petros and petra—two different terms.

Second, what about the claim that these two terms were identical in meaning by the time the NT was written? It is probably the case that by this time the terms had drawn closer together in meaning, and that petros could be used with the same connotation as petra. But that does NOT require us to think that every time petros was used, it had to be identical or synonymous with petra – especially when they were used together, as in the case of Matthew 16:18. Users of these words, especially the Holy Spirit, would be aware of the history of their usage and could make a point from it when appropriate. (See Lenski, op. cit., 625). As Colin Brown says, “The two words could be used interchangeably,” but “could be” does not mean “always were.” (See Brown, “Rock,” The New International Dictionary of NT Theology, Baker 1978, 3:386.)

But what about the point that the only reason Petros is used for Peter, instead of petra, is the gender requirement of the Greek language – that a masculine ending had to be used for a male name? This is certainly the way it usually occurred, but that was not the reason for changing petra to Petros here. The fact is that Jesus had already re-named Simon as Petros (in Greek) in John 1:42 and Mark 3:16. The Greek word Petros is used 154 times in the NT, always in reference to Peter. In the Gospel records Jesus addresses Peter ten times, using “Simon” eight times and “Peter” twice (Matt. 16:18 and Luke 22:34). Here in Matt. 16:18 Jesus is simply using the Greek name by which Peter is known throughout the NT.

But surely, the fact that Petros means “rock” in some sense must be significant, or Jesus would not have given Peter this new name (or nickname) in the first place. I agree with that – but which connotation did Jesus have in mind when he called Simon “Cephas”: large bedrock (petra) or small movable stone (petros)? The interesting thing is that in the Luke 22:34 text – the only other place Jesus is recorded as addressing Peter as Petros, Peter’s status and demeanor as a rock are more like the small pebble than a large, immovable stone. I.e., here, Jesus is informing the over-confident Peter that he is about to fail: “I tell you, Peter, the rooster will not crow this day, until you deny three times that you know me” (ESV). This hardly pictures Peter as a petra!

This is something we must keep in mind when we read Matthew 16:18, which is the only other place where Jesus is pictured as actually using Peter’s Petros name. And in view of Matthew 16:17 (see below), it makes perfect sense to say that Jesus is here emphasizing Peter’s weaker side: “You are a petros, not a petra!”

Third, I have acknowledged that Petros and petra could be and no doubt were, at times, used interchangeably in the NT era, but I insist that it was not always necessarily the case that they were equivalent or synonymous. I suggest that this equivalence could apply when either word was being used singly, apart from the other; but if the two words are being used together, as in Matthew 16:18, we should look for a valid textual reason why both might be used with their individual connotations.

But would not the gender requirement (discussed above) be a sufficient reason? Not really. Even if Jesus (or the Holy Spirit inspiring the Greek text) wants to retain Petros as the masculine name of Peter while equating it with the second “stone” word, he could have used petros in the second statement: “You are Petros – and on this petros I will build my church.” But then the Catholic defender will say, “No! Petros is a small stone! The church must be built on a firm foundation-rock – a petra!” Oh, really? But does not the Catholic argument adamantly say there is no distinction between these terms in NT times? So why could petros not have been used in both statements, if Peter and the foundation stone are the same thing?

Fourth and finally, what we must decide, in v. 18, is whether Jesus intended to EQUATE the Petros and the petra, or to DISTINGUISH them. The Roman Catholic Church, as represented by Keating, says the former; I say the latter. Why? First of all, if Peter and the foundation stone are meant to be the same, why did Jesus not simply say, “You are Peter, and ON YOU I will build my church”? As Lenski says (p. 625), “If by ‘this rock’ Jesus had Peter in mind, he could easily have said, epi sou, ‘on thee’ will I build my church, or ‘on thee, Peter,’ adding his name.” But Jesus did not say it this way.

Next, continuing to analyze the context, we can identify another textual reason why Petros and petra in verse 18 should be distinguished and not equated – a reason which we must not overlook. In verse 16, Peter makes his grand confession, “You are the Christ, the Son of the living God.” Then in verse 17 Jesus says, “Blessed are you, Simon Barjona, because flesh and blood did not reveal this to you, but My Father who is in heaven.” I.e., Jesus praises Peter for his confession, but he makes clear that Peter himself is not the source of this knowledge. The source is the heavenly Father. The point of verse 17, then, is to distinguish Peter, in his “flesh and blood” weaknesses and limitations, from the Almighty and All-knowing God. So in verse 17, Jesus has already cited Peter’s weak nature (see Luke 22:34), in contrast with the supernatural; then in verse 18 he reaffirms this contrast thus: “Yes, Petros, you are a rock, but a small one in contrast with this other Rock, this petra that the Father has revealed to you and upon which I will build my church.”

In conclusion, what is this petra on which the church is built? It is the CONTENT of Peter’s confession, which sums up the work of Jesus (“the Christ”) and the person of Jesus (“the Son of the living God”). In this sense it is Jesus himself who is the petra, the foundation stone of the church – not any mere human being, including Peter (see 1 Cor. 3:11). In the sense that the church is built on the content of apostolic teachings about Christ, it is not the one apostle, Simon Peter, who is that foundation, but ALL the Holy Spirit-inspired apostles and prophets (Eph. 2:20). In this latter text, Peter is not given any priority over the other apostles – a fact that confirms our present explanation of Matthew 16:18.