Jesus spoke Aramaic. The word for rock IN Aramaic is Kepha. There no difference between small or big rock.
Jesus said unto Simon Peter,
Blessed are you Simon, Bar Jona! For flesh and blood has not revealed this to you, but My Father who is in heaven. And I tell you, you are Kepha, and On this Kepha I will built My Church, and the powers of death shall not prevail against it. (Catholic Bible RSV).
Peter was blessed because he believed and confessed that Jesus was the Christ. He was saved by his confession.
Rom 10:10 For with the heart man believeth unto righteousness; and
with the mouth confession is made unto salvation.
Jesus built Only One Church. He built it upon Simon Peter, and Jesus grafted Peter into Himself. In the Catholic Church, the Head is Jesus Christ. Peter is his stewart of His Kingdom, a Prime Ministerial Office a post held temporary post until the King returns.
Jesus is in indeed the rock but Jesus in this passage is not the Rock. He said, You ARE KEPHA!"
This is plainly clear that Jesus built His Church upon Peter.
Jesus built His church on a confession that is believed in the heart. He who believes and turns from their sins is saved. Let’s see what the Word of God has to say.
Mar 9:23 Jesus said unto him, If thou canst believe, all things [are] possible
to him that believeth.
Jhn 3:15 That
whosoever believeth in him should not perish, but have eternal life.
Jhn 3:16 For God so loved the world, that he gave his only begotten Son, that
whosoever believeth in him should not perish, but have everlasting life.
Jhn 3:18
He that believeth on him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God.
Jhn 3:36
He that believeth on the Son hath everlasting life: and he that believeth not the Son shall not see life; but the wrath of God abideth on him.
Jhn 5:24 Verily, verily, I say unto you,
He that heareth my word, and believeth on him that sent me, hath everlasting life, and shall not come into condemnation; but is passed from death unto life.
Jhn 6:40 And this is the will of him that sent me, that every one which seeth the Son, and
believeth on him, may have everlasting life: and I will raise him up at the last day.
Jhn 12:44 Jesus cried and said,
He that believeth on me, believeth not on me, but on him that sent me.
Act 10:43 To him give all the prophets witness, that through his name
whosoever believeth in him shall receive remission of sins.
Rom 3:26 To declare,
, at this time his righteousness: that he might be just, and the justifier of him which believeth in Jesus.
Rom 4:5 But to him that worketh not, but believeth on him[his faith is counted for righteousness that justifieth the ungodly, .
Rom 9:33 As it is written, Behold, I lay in Sion a stumblingstone and rock of offence: and whosoever believeth on him shall not be ashamed*.
Rom 10:11 For the scripture saith, Whosoever believeth on him shall not be ashamed.*