Well, first of all this answer deals with your interpretation of the scripture. Most people know that Matthew 16:18 is a play on words with Peter’s name meaning rock. However, there is more significance in what Jesus said. Peter’s name in greek is PETROS,but the lord used the feminine PETRAS in this scripture which has a distinct meaning. Petro is an isolated rock, stone, or pebble which could be hewn from a more solid and greater bedrock (PETRA). So what was the Lord referring to when he used petra. Well, if you take it in context of the story, you will see that Jesus told Peter this right after he bore testimony of Jesus. The Lord blessed him because that testimony was “REVEALED from his Father in Heaven” Immediately after this that the Lord says “thou art Peter and upon this rock (Meaning PETRA or revelation from God) I will build my church” This makes perfect sense if one considers that God has always directed his people and his church through revelation. Peter or Petros was truly a rock hewn from a solid foundation or bedrock (Petra)…God!!!
As for the Mormon belief of Apostasy, they get from “revelation” which is substantiated by the Bible. Paul, when speaking to the Thessalonians about the RETURN of Christ said, "for that day shall not come, except their be a FALLING AWAY first’. Other scriptures include ( Acts 20:29, Gal 1:6, 2Tim 3:5,)
I think you are mistaken. Please see the following from Catholic Answers, which gives an explanation of the Greek and Aramaic roots of the passage. I apologize for the length… I haven’t learned how to “link” to information. If you want to skip this, you can look it up on Catholic Answers main page by following “Church & Papacy” and “Peter the Rock.”
Thankyou,
RAR
Code:
"No," I answered. "Many, if not most of them, knew Greek, of course, because Greek was the *lingua franca* of the Mediterranean world. It was the language of culture and commerce; and most of the books of the New Testament were written in it, because they were written not just for Christians in Palestine but also for Christians in places such as Rome, Alexandria, and Antioch, places where Aramaic wasn’t the spoken language.
“I say most of the New Testament was written in Greek, but not all. Many hold that Matthew was written in Aramaic—we know this from records kept by Eusebius of Caesarea—but it was translated into Greek early on, perhaps by Matthew himself. In any case the Aramaic original is lost (as are all the originals of the New Testament books), so all we have today is the Greek.”
I stopped for a moment and looked at the missionary. He seemed a bit uncomfortable, perhaps doubting that I was a Catholic because I seemed to know what I was talking about. I continued.
Aramaic in the New Testament
"We know that Jesus spoke Aramaic because some of his words are preserved for us in the Gospels. Look at Matthew 27:46, where he says from the cross, ‘
Eli, Eli, lama sabachthani?’ That isn’t Greek; it’s Aramaic, and it means, ‘My God, my God, why have you forsaken me?’
“What’s more,” I said, "in Paul’s epistles—four times in Galatians and four times in 1 Corinthians—we have the Aramaic form of Simon’s new name preserved for us. In our English Bibles it comes out as
Cephas. That isn’t Greek. That’s a transliteration of the Aramaic word
Kepha (rendered as
Kephas in its Hellenistic form).
"And what does
Kepha mean? It means a rock, the same as
petra. (It doesn’t mean a little stone or a pebble. What Jesus said to Simon in Matthew 16:18 was this: ‘You are
Kepha, and on this
kepha I will build my Church.’
“When you understand what the Aramaic says, you see that Jesus was equating Simon and the rock; he wasn’t contrasting them. We see this vividly in some modern English translations, which render the verse this way: ‘You are Rock, and upon this rock I will build my church.’ In French one word,
pierre, has always been used both for Simon’s new name and for the rock.”
For a few moments the missionary seemed stumped. It was obvious he had never heard such a rejoinder. His brow was knit in thought as he tried to come up with a counter. Then it occurred to him.
“Wait a second,” he said. “If
kepha means the same as
petra, why don’t we read in the Greek, ‘You are
Petra, and on this
petra I will build my Church’? Why, for Simon’s new name, does Matthew use a Greek word,
Petros, which means something quite different from
petra?”
“Because he had no choice,” I said. "Greek and Aramaic have different grammatical structures. In Aramaic you can use
kepha in both places in Matthew 16:18. In Greek you encounter a problem arising from the fact that nouns take differing gender endings.
"You have masculine, feminine, and neuter nouns. The Greek word
petra is feminine. You can use it in the second half of Matthew 16:18 without any trouble. But you can’t use it as Simon’s new name, because you can’t give a man a feminine name—at least back then you couldn’t. You have to change the ending of the noun to make it masculine. When you do that, you get
Petros, which was an already-existing word meaning rock.
“I admit that’s an imperfect rendering of the Aramaic; you lose part of the play on words. In English, where we have ‘Peter’ and ‘rock,’ you lose all of it. But that’s the best you can do in Greek.”