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Matthew 16:13 Now when Jesus came into the district of Caesarea Philippi, He was asking His disciples, "Who do people say that the Son of Man is?"

16:14 And they said, "Some say John the Baptist; and others, Elijah; but still others, Jeremiah, or one of the prophets."

16:15 He said to them, "But who do you say that I am ?"

16:16 Simon Peter answered, "You are the Christ, the Son of the living God."

16:17 And Jesus said to him, "Blessed are you, Simon Barjona, because flesh and blood did not reveal this to you, but My Father who is in heaven.

16:18 "I also say to you that you are Peter, and upon this rock I will build My church; and the gates of Hades will not overpower it.
He says "you are petros", which means a small stone. And "upon this petra", petra means huge rock or monolith, in which case He is talking about Himself. He is not telling Simon Peter that He will build His church (actually Ekklesia, a gathering called out.) on Simon Peter.

16:19 "I will give you the keys of the kingdom of heaven; and whatever you bind on earth shall have been bound in heaven, and whatever you loose on earth shall have been loosed in heaven."
They cannot bind or loose anything contrary to the laws of God

16:20 Then He warned the disciples that they should tell no one that He was the Christ.
They were to tell no one that He was the Christ! Obviously He is not trying to save the world. His purpose was to overcome Satan and qualify to replace him as world ruler, then be sacrificed to pay the penalty of sin for all mankind, and be resurrected to eternal life, the first of many brothers.There is no calling of the world in general until the 2nd resurrection, about 1000 years after the return of Christ.

1 Corinthians 15:20 But now Christ is risen from the dead, and has become the firstfruits of those who have fallen asleep. 21 For since by man came death, by Man also came the resurrection of the dead.
22 For as in Adam all die, even so in Christ all shall be made alive. 23 But each one in his own order: Christ the firstfruits, afterward those who are Christ's at His coming.
After His coming He will rule for 1000 years. Notice Christ first, then those who are Christs (the ekklesia: called out ones). His church lives on earth through the tribulation. There is no rapture. And the dead are just that, dead. They do not know the passing of time, like a deep sleep.

John 3:13 No one has ascended to heaven but He who came down from heaven, that is, the Son of Man who is in heaven

Revelation 5 But the rest of the dead did not live again until the thousand years were finished.