Jesus was speaking of Himself, not Peter.
Matt 16:16-18
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. KJV
The specific words that are key to understanding this are “Peter” and “rock,” for they are both derivatives of the same word meaning rock. But the word translated to “Peter” in the verse above (and below) is petros, and the word translated to “rock” is petra. Also, the word “rock” below has the definite article in the Greek (although it is not seen in the English language translation), whereas the word “Peter” (although capitalized in the English translation) does not have the definite article. (Illustration to follow.)
Code:
But simply stated, a petros is a small rock; while petra is a large rock, even a solid foundation of stone.
Matt 16:18
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. KJV
Peter: Greek word #4074 Petros (pet’-ros); apparently a primary word; a (piece of) rock (larger than NT:3037); as a name, Petrus, an apostle: KJV - Peter, rock. Compare NT:2786.
rock: Greek word #4073 petra (pet’-ra); feminine of the same as NT:4074; a (mass of) rock (literally or figuratively): KJV - rock.
(The definite article): Greek word #3588 ho (ho); including the feminine he (hay); and the neuter to (to); in all their inflections; the def. article; the (sometimes to be supplied, at others omitted, in English idiom): KJV - the, this, that, one, he, she, it, etc…
Code:
Below is a copy of the original Greek words of the key part of the verse. Notice the definite article (tee -Grk. word #3588) preceding "rock":
Also, the word "and" (between "Peter" and "upon") in the above illustration is kai in the Greek and can also be translated to the word "but" in the English. This of course changes the way that this verse is commonly understood. Observe:
and: Greek word #2532 kai (kahee); apparently, a primary particle, having a copulative and sometimes also a cumulative force; and, also, even, so then, too, etc.; often used in connection (or composition) with other particles or small words: KJV - and, also, both, but, even, for, if, or, so, that, then, therefore, when, yet.
But to give you a sense of the meaning of the word petra (“rock”), there is a city carved out of the side of a mountain, located in modern day Jordan, which is called Petra. “Peter” (petros) was a movable stone, a smaller piece; petra (translated “rock”) was a solid foundation; and incidentally, that Rock was Christ:
1 Cor 10:4
4 And did all drink the same spiritual drink: for they drank of that spiritual Rock [petra] that followed them: and that Rock [petra] was Christ. KJV
Rock: Greek word #4073 petra (pet’-ra); feminine of the same as NT:4074; a (mass of) rock (literally or figuratively): KJV - rock.
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