21st Sunday in Ordinary Time, Matthew 16:13-20
And so I say to you, you are Peter, and upon this rock I will build my church, and the gates of the nether world shall not prevail against it.
It is well know that the name “Peter” (Petrus or Petros) means “Rock” and, as Christians have always understood it, our Savior gave Simon this name in order to signify that he is the “rock” upon which the Church is founded.
However, a difficulty arises, for we know that Christ alone is the true foundation of the Church – If Jesus Christ is the “Rock”, how can Peter be the “Rock”?
Are “Peter” and “rock” identical words?
Many protestants will claim that, while Christ called Simon son of Jona “Rock”, he did not refer to him as the rock upon which the Church is founded. By their interpretation, the words this rock (in the phrase and upon this rock I will build my church) do not refer to Peter because the words “Peter” and “rock” are supposedly not identical.
While it is true that the name “Peter” and the word “rock” are not identical in Greek – “Peter” or “Petros” is masculine, while “rock” or “petra” is feminine – it is important to notice that the words are identical in Aramaic (which is the language in which Jesus original spoke them). The Aramaic name “Peter” is “Kepha” and this is identical to the word “rock” (also “kepha”). Hence, it should be very clear that the meaning of the phrase is best expressed in English as follows: “You, Simon, are Rock and upon this rock I will build my Church.”
Peter is “the rock”, but is he “this rock”?
Nor can any claim that that our Lord did not intend St. Peter when he said this rock. On this point, consider the commentary of Fr. Cornelius a’ Lapide:
“That Peter is here called the Rock, is proved first, by the pronoun ‘this,’ upon ‘this rock;’ for since ‘this’ is demonstrative it ought thus to be understood, viz.:—this rock of which I have spoken, and to whom I speak, i.e., thou art Peter the rock of the Church, and upon thee as upon a rock I will build My Church. For there had been no mention made of any other rock to which the pronoun ‘this’ could refer, except Peter.
“Secondly—The same thing is plain from this, that there would be a want of connection to say thou art Peter and upon Myself the Rock I will build My church. In this indeed there would be a lessening of the speech, and an overthrow of the benefit bestowed. For Peter might say to Christ, ‘I am Peter, that is the rock of the Church, how then dost thou build Thy Church not upon me but upon Thyself?’
“Thirdly—Because all that goes before and that follows refer to Peter alone: ‘and I,’ he saith, ‘say to thee, o Peter, that is, I give and assign to thee as the reward and prerogative of thy great faith and confession, that after Myself, and after My death and resurrection, I will make thee the rock and foundation of the Church;’ for this is the meaning of I will build My Church.”
Christ is the Rock and Peter is the Rock
Finally, we come to our original difficulty: How can it be that Peter is the foundation and rock of the Church, when we know that the one foundation of the Church is Jesus Christ her Lord? If Jesus is the Rock, how can Peter also be the Rock?
To understand this point, we must know something of primary and secondary causality – which is precisely what the protestant reforms did not understand. It is possible for an action to be completed by two agents who are full and perfect authors of the single action, so long as the two agents do not operate on the same level of causality. Thus, we are able to have a primary cause which is the cause of an action and also a secondary cause which is also the cause of the same action.
Consider an analogy: If a man writes a word with a pencil and we ask, “Who/what wrote this?” We would be correct to say that the pencil wrote it and also to say that the man wrote it. And it is not that the man wrote part and the pencil wrote part, but the man wrote the whole and the pencil wrote the whole – and yet only one thing was written and there was only one act of writing.
Similarly, we may claim that the human authors of the Scriptures were true authors, while also maintaining that God is the primary author of the Bible. The individual men were secondary causes, but God was the primary cause – hence, there was only one thing written and only one act of writing; though both God and the individuals were true authors.
Now, we turn to the case of the foundation of the Church: Christ is the Rock in the sense of primary causality, but Peter is the Rock according to secondary causality. As St. Matthew is the author of a book which has God as its primary author, so too we assert that St. Peter is the foundation of the Church which has Christ as its primary foundation.
When Christ our Savior gave Simon the name Peter, he communicated a share in his own name and mission. As Peter is strengthened by Christ’s strength, there is no danger in affirming that Peter is the rock and foundation of the Church while also affirming that her sole foundation is the one Rock which is Christ the Lord.