Matthew 16:18 - http://bible.cc/matthew/16-18.htm
Jesus said that Peter was *petros*(masculine) and that on this *petra*(feminine) He would build His church.
Greek: 4074 Pétros (a masculine noun) – properly, a stone (pebble), such as a small rock found along a pathway. 4074 /Pétros (”small stone”) then stands in contrast to 4073 /pétra (”cliff, boulder,” Abbott-Smith).
“4074 (Pétros) is an isolated rock and 4073 (pétra) is a cliff” (TDNT, 3, 100). “4074 (Pétros) always means a stone . . . such as a man may throw, . . . versus 4073 (pétra), a projecting rock, cliff” (S. Zodhiates, Dict).
4073 pétra (a feminine noun) – “a mass of connected rock,” which is distinct from 4074 (Pétros) which is “a detached stone or boulder” (A-S). 4073 (pétra) is a “solid or native rock, rising up through the earth” (Souter) – a huge mass of rock (a boulder), such as a projecting cliff.
4073 (petra) is “a projecting rock, cliff (feminine noun) . . . 4074 (petros, the masculine form) however is a stone . . . such as a man might throw” (S. Zodhiates, Dict).
It’s also a strange way to word the sentence that He would call Peter a rock and say that on this I will build my church instead of *on you* as would be grammatically correct in talking to a person.
There is no support from the original Greek for the idea that Jesus meant Peter to be that which He was going to build His church on. The nouns are not the same as one is feminine and the other masculine and denote different objects.
Actually there are some Orthodox who agree that “rock” refers to Peter.
Unlike the Catholic Church, however, I do not believe that the Orthodox is uniform in their belief on the primacy of Peter. It is my understanding that generally speaking Orthodox agree that Peter is the first among equals (and therefore holds a special place). It, however, does not agree that he is Supreme (ie. Primacy vs Supremacy).
Matthew 18 And I tell you, you are Peter(The Rock),[d] and on this rock[e] I will BUILD MY church, and the powers of death[f] shall not prevail against it.[g] 19 I will give you the keys of the kingdom of heaven,[h] and whatever you bind on earth shall be bound in heaven, and whatever you loose on earth shall be loosed in heaven.”
"And I Tell YOU, YOU ARE PETER" He changed the name Simon to PETER. Which means ROCK.
When God Changes names something is happening here. Peter is the Rock. He is addressing PETER without a doubt.
When I say in a conversation " And I TELL YOU" I am pointing out to you . He is obviously addressing To the one he is talking at in the conversation.
Then if I would put "YOU ARE PETER" I am emphazing you are the ROCK also to the next words- " and on this ROCK I will BUILD MY church, and the powers of death[f] shall not prevail against it.[g]
19 I will give YOU the KEYS of the kingdom of heaven,[h] and whatever you bind on earth shall be bound in heaven, and whatever you loose on earth shall be loosed in heaven.”
He is addressing "The Rock"that was named by him. PETER.
Also when you give Keys those Keys are to be passed on to someone responsible as a leader. I have a house with keys. I only pass them on to who is to be trusted.
Peace in Christ to You.