Greek: 15 λέγει αὐτοῖς· ὑμεῖς δὲ τίνα με λέγετε > εἶναι; 16 ἀποκριθεὶς δὲ Σίμων Πέτρος εἶπεν· σὺ εἶ ὁ Χριστὸς ὁ υἱὸς τοῦ θεοῦ τοῦ ζῶντος. 17 ἀποκριθεὶς δὲ ὁ Ἰησοῦς εἶπεν αὐτῷ· μακάριος εἶ, Σίμων Βαριωνᾶ, ὅτι σὰρξ καὶ αἷμα οὐκ ἀπεκάλυψέν σοι ἀλλ’ ὁ πατήρ μου ὁ ἐν τοῖς οὐρανοῖς. 18 κἀγὼ δέ σοι λέγω ὅτι σὺ εἶ Πέτρος, καὶ ἐπὶ ταύτῃ τῇ πέτρᾳ οἰκοδομήσω μου τὴν ἐκκλησίαν, καὶ πύλαι ᾅδου οὐ κατισχύσουσιν αὐτῆς. 19 δώσω σοι τὰς κλεῖδας τῆς βασιλείας τῶν οὐρανῶν, καὶ ὃ ἐὰν δήσῃς ἐπὶ τῆς γῆς ἔσται δεδεμένον ἐν τοῖς οὐρανοῖς, καὶ ὃ ἐὰν λύσῃς ἐπὶ τῆς γῆς ἔσται λελυμένον ἐν τοῖς οὐρανοῖς.
My Translation: 15 He says to them, "But who do you > all say that I am?" 16 Yet Simon Peter answering said, "You are the christ, the son of the living god." 17 And Jesus answering said to him, "You are happy, Simon Barjona, because flesh and blood did not uncover this to you, but rather your father who is in the heavens. 18 And I myself also say to you, you are Petros [a stone], and upon this crag [petra] I will build my assembly, and the entrances of Hades will not overcome her. 19 And I will give to you the keys of the kingdom of the heavens, and whatever if you might bind it on the earth it will be bound in the heavens, and whatever if you might loosen on the earth it will be loosened in the heavens."
KJV: 15 He saith unto them, But whom say ye that I am? 16 And Simon Peter answered and said, Thou art the Christ, the Son of the living God. 17 And Jesus answered and said unto him, Blessed art thou, Simon Barjona: for flesh and blood hath not revealed it unto thee, but my Father which is in heaven. 18 And I say also unto thee, That thou art Peter, and upon this rock I will build my church; and the gates of hell shall not prevail against it. 19 And I will give unto thee the keys of the kingdom of heaven: and whatsoever thou shalt bind on earth shall be bound in heaven: and whatsoever thou shalt loose on earth shall be loosed in heaven.
My translations are purposefully stretched and should not be viewed as more accurate than the KJV translation unless I say so in the post. I'm trying to show the range lying between the original Greek text and the English.
Finally, three scriptures in and we hit a doozy! The keys of the kingdom, given to Peter, and the cryptic phrase, "You are Peter and upon this rock I will build my Church". A similar scripture is found in Mark, but in his editing of Mark, Matthew has added this statement of Jesus in response to Peter's declaration, that Jesus's church would be built on this rock (note that Peter's name means "rock") and that Peter would be given the keys of the kingdom, all of which is absent in the original material of Mark.
The reason this is a doozy is because this scripture is viewed by many Christians, predominantly Catholics but also many Protestants, as the divine call for Peter to lead the church, while for Mormons it is viewed as a statement that the Church of Christ is built upon the foundation of revelation. It's an important distinction, and we'll take a look at it.
First, though, a few translation points. Again, remember that the translation I'm providing, while still correct, is by design a little strained. It's meant to show which words in the more-familiar King James translation have a wider meaning than the given English. One example is the word ecclesia, "church". It literally means a gathering, or a group "called out". And in Greek it would not have meant "church" as Mormons or Christians today use it. There are other examples of ecclesia in the Greek-speaking world, and it might make more sense to translate the word as "club". Ecclesia weren't always religious in nature, but could be organized around cultural groups, philosophical groups, or political groups. Jesus saying, however, that his ecclesia would be built upon "this rock" (we'll get to that issue in a moment) is slightly out of character from the other gospels. Of the four Gospel-writers, only Matthew is particularly focused on this idea of Jesus's ecclesia. The word is used in Matthew's Sermon on the Mount and other places within his gospel, but is entirely absent in the other gospels. Matthew is also uniquely focused on the rules of a Christian community, with a focus, as we've discussed before, on the Jewish Torah. Whereas in other gospels Jesus presents a view of Torah as a code not always to be followed (or even followed at all), Matthew presents a view of Jesus where Torah and its observation is still supremely important for Jesus and his followers. Matthew's Jesus is the one who says that not one jot nor tittle of the law had been done away with.
Why does any of this matter? Because these books and these scriptures were not written in a vacuum. The books and letters of the New Testament had human authors, inspired though you may feel they were, and these authors did not always see eye to eye. By the time the Gospel of Matthew, as we have it today, was being produced there were already a number of different Christian communities throughout the eastern Roman Empire. We know this because the oldest Christian writings are not any of the Gospels, but are rather the letters of Paul, written to many of these various communities (and in fact, Matthew isn't even the first gospel to be written; Matthew makes extensive editorial use of the gospel of Mark in writing his gospel). And Paul presents a picture of Christian doctrine and practice quite different from what the author of Matthew presents.
We'll talk more about Paul when we reach his letters, but a short overview of his life is that he was born a Jew, was originally opposed to those who believed Jesus to be the Jewish Messiah, and had some sort of experience that changed his mind to also believe that Jesus has risen from the dead as the Messiah (recorded as a vision by the author of Luke, though Paul himself says very little about the experience). Paul's theological attempts to understand the significance and meaning of Jesus's death and apparent resurrection (Paul himself joined the movement long after the death of Jesus, but he believed as most Jesus followers did that Jesus literally died when he was executed and rose alive again after three days) helped him to reach some rather radical theological conclusions about the necessity of the Jewish Torah. As he relates in his letter to the Galatians, these ideas of his led him to occasionally clash with other Jesus followers, most famously against Simon Peter while he was visiting Jerusalem. Peter was observing Jewish purity practices about not eating meals with Gentiles, and Paul rebuked him for it. Many of Paul's letters provide details showing that this issue of whether Jesus followers, both Gentile and Jewish, should follow Torah was one of the major dividing issues among early Christians. They also show that many Christians of Paul's day appealed to the authority of various Christian leaders in support of their viewpoints. Some of Paul's opponents who apparently felt that followers of Jesus needed to observe Torah called themselves apostles, though whether these included any of the traditional apostles named in the Gospels is unknown.
So among these leaders, we know that the famous names of authority included Paul, Peter, and James (in fact, the Acts of the Apostles, the sequel to Luke, seems to give James narrative supremacy over Peter when the movement has to make decisions about Paul and the Gentiles). Given Peter's occasional opposition to Paul, it might be that this verse in Matthew represents the author's attempt to place Peter as a higher authority to Paul: not only was he among the original disciples of Jesus, but Jesus gave him "the keys of the kingdom". This is only supposition, of course, and is not in any way a provable hypothesis.
This leads to the other issue at hand: the "rock" upon which the ecclesia is built. In the Greek, there is an undeniable relationship between the name Peter ("a stone"0 and the rock ("a crag, a cliff, a rock"). Something is implied by Matthew's Jesus in this phrase, and the issue is what that something might be. The traditional Catholic reading is that Jesus is making a pun, and that both rocks are the same: in other words, Jesus will built his ecclesia upon Peter. The tradtional Protestant reading is either the same as the Catholics, or that the foundation in question is Peter's faith in Jesus as the Messiah (not faith in general, but Peter's specific declaration that Jesus is the Christ).
The Mormon reading for this verse comes from some handwritten notes taken during a sermon given by Joseph Smith in 1843. In these notes, the author, Wilford Woodruff, records that Joseph asked, "And what is that rock?" with the answer, "The rock of revelation". So for Joseph Smith the relationship between the two rocks is that Peter, the one rock, had received revelation from the Father in Heaven when he proclaimed that Jesus was the Messiah. This is the other rock, and the ecclesia was to be built upon this foundation of revelation, at least if this one reference represents Joseph's full feelings on the matter.
One aspect of this interpretation that is useful for Mormons is how it changes the interpretation of the next aspect of the verses: the reference to the gates of Hell. From a Mormon point of view, true Christian doctrine was lost soon after the death of the Apostles leading to a period of nearly two thousand years where God's authority and true teachings were not present on earth. This is called the Great Apostasy, and was ended in 1820 when Joseph Smith received what became known as his first vision. If Jesus's statement about how his church was founded upon the rock is referring to Peter, then Mormons have a problem, because they feel that the organization led by Peter, which eventually became the Catholic Church and many other churches from it, was overcome. What then of the statement of Jesus that the Church would not be prevailed against? Well, if the rock is instead a concept of revelation, then it's much easier to deal with the verse: God never took the ability for his children to be led by revelation away. So that rock has always remained.
Is there any foundation for the interpretation of the rock being revelation in the original Greek? Sorta, but if that was what was mean by Matthew's Jesus then it really isn't very clear. The statement uses two extremely similar words, begins with the declarative statement, "You are Peter" (which was not Peter's actual name; his name was Simon), and makes a connection based on this image of a rock upon which a structure can be built. Simon is a rock, and the ecclesia is built on a rock. If the relationship is more nuanced than a direct correlation then the text itself does a poor job of showing that nuanced relationship. The easiest reading, which doesn't automatically mean the most correct, would be that Matthew has Jesus saying that his ecclesia would be built upon Peter. But to imply that the Mormon reading is the only valid interpretation without some flavor of a relationship between Peter's authority (symbolized by receiving keys to the kingdom of heaven) and the building of a church upon a rock is silly.
Finally, what are we to make of the reference to Peter's ability to tie up tightly or loose on earth and in the heavens? Remember that for those with an apocalyptic worldview, the coming kingdom will violently overthrow the world. That is because it is a literal kingdom that is approaching (contrast this to the later Gospel of John, which tones down this "approaching" rhetoric when Jesus says things like "the Kingdom of God is among you"), and it will replace the evil powers currently controlling this world. And in that coming kingdom, those who have been oppressed will be lifted up. Total reversals will occur (go back and read the Beatitudes of Matthew 5 in this light and they make a lot of sense). Peter is being told that he is like a ruler in this world, and that his decisions here will stand and be ratified in the coming kingdom. Whatever, or indeed whoever, he ties up or frees will remain tied up or freed. This is language that is likened to the most powerful aspect of a ruler: the ability to lock up or the ability to pardon. The Mormon perception of the "sealing" power is similar to this viewpoint, however, in that Mormons view Peter being given authority here to make decisions with heavenly ramifications, except that for Mormons they feel that this power means that the decisions have immediate authority and application in heaven and not merely that these decisions will remain in force when a future heavenly kingdom arrives.
Why Do I Think This Is Part of Scripture Mastery?
In preparation for use of this scripture against their conception of a universal apostasy, Mormon youth are prepped with this verse and an alternate interpretation that preserves their viewpoint. This interpretation is a valid reading, but it is extremely difficult to parse and is not the easiest nor most likely reading.