Anti-Catholics have a big investment in showing that Peter is not the rock on which Jesus said he would build his Church. Although this is the plain meaning of Christ’s words in Matthew 16:18, the early Reformers—and anti-Catholics ever since—have had to argue that Peter was not the rock in order to undermine the authority of the pope and to justify having broken away from the Church.
The passage anti-Catholics most often cite to argue against the Church being founded on Peter is 1 Corinthians 3:10–11: “[L]ike a skilled master builder I laid a foundation, and another man is building upon it. Let each man take care how he builds upon it. For no other foundation can any one lay than that which is laid, which is Jesus Christ.”
In this passage Paul is not claiming to have laid the foundation of the universal Church (after all he wasn’t even a Christian when that was done), only the foundation of the local Church at Corinth. Thus he is speaking of Christ as the foundation of the local, not the universal, Church.
One can go beyond the literal meaning of the text and extend it to include the universal Church, but not without taking into account everything else the New Testament has to say about the Church’s foundation. This is a problem for the anti-Catholic, since 1 Corinthians 3 is only one of five places where the Church’s foundation is discussed, and in them the same metaphor is never used twice.
For anti-Catholics, the second most popular of the five passages is 1 Peter 2:6, where Isaiah 28:16 is applied to Christ: “Behold, I am laying in Zion a stone, a cornerstone chosen and precious, and he who believes in him will not be put to shame.”
This is irresistible to the anti-Catholic. “Man, that’ll preach, brother, that’ll preach! Peter himself declares Christ to be the rock!”
But the word for “stone” here isn’t petros—the name Jesus gave Peter (John 1:42)—it’s lithos, a completely different word. (Lithos is the everyday word for stone; petros is an uncommon synonym, which makes its use as Peter’s name and in Matthew 16:18 all the more striking.)
More important, 1 Peter 2:6 says Jesus is the Church’s cornerstone, not its foundation. A cornerstone is only one piece of a foundation (the corner part of it), and this doesn’t exclude other pieces.
Want proof? Turn to another of the five passages, Ephesians 2:20, which says the household of God is “built upon the foundation of the apostles and prophets, Christ Jesus himself being the cornerstone.”
The prophets here are not the writers of the Old Testament but prophets of the New Testament age, as made clear by the two other references to them in the epistle (Eph. 3:5, 4:11).
Together with the apostles, they form the Church’s foundation in this passage, which was written by the same apostle who wrote 1 Corinthians 3:11, showing there was no contradiction in his mind between Christ being the foundation in one sense and others being the foundation in another.
The fourth passage is Revelation 21:14, where New Jerusalem is said to have not one foundation, but twelve, with the names of the apostles. This is a select group, including only the eleven who were apostles during Christ’s earthly ministry, plus Matthias (Acts 1:26). Not even Paul and Barnabas, who also were called apostles (Acts 14:14), were members of the Twelve.
The fifth passage is, of course, Matthew 16:18: “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.”
For many reasons, this passage must be interpreted to mean that, in one sense, Peter is the rock on which the Church is built, but the point to be made here is that there is not simply one metaphor in Scripture for the Church’s foundation. There are five.
In 1 Corinthians 3, Christ is the foundation of the local Church. In 1 Peter 2, Christ is the cornerstone of the Church. In Ephesians 2, Christ is the cornerstone with the apostles and New Testament prophets as the foundation. In Revelation 21, the foundation is the Twelve. And in Matthew 16, the rock is Peter.
Every one of these assertions is true, but each in a different sense. One must read each passage in its own context, discern its meaning, and then harmonize it with the other five passages. One cannot take one’s pet passage and stuff its meaning into the other four. For anti-Catholics to take 1 Corinthians 3—or any passage—and stuff its meaning into Matthew 16 is as wrong as if Catholics were to take Matthew 16 and stuff its meaning into the other four.