Jesus gave Peter the keys of the Kingdom of Heaven. I’ll quote the NIV,Matthe Chapter 16: "13 When Jesus came to the region of Caesarea Philippi, he asked his disciples, “Who do people say the Son of Man is?”14 They replied, “Some say John the Baptist; others say Elijah; and still others, Jeremiah or one of the prophets.”15 “But what about you?” he asked. “Who do you say I am?”
16 Simon Peter answered, “You are the Messiah, the Son of the living God.”17 Jesus replied, “Blessed are you, Simon son of Jonah, for this was not revealed to you by flesh and blood, but by my Father in heaven. 18 And I tell you that you are Peter,** and on this rock I will build my church, and the gates of Hades[c] will not overcome it. 19 I will give you the keys of the kingdom of heaven; whatever you bind on earth will be[d] bound in heaven, and whatever you loose on earth will be[e] loosed in heaven.”
I would encourage you to meditate on this passage and compare it with Isaiah 22:20-22 where God does practically the same thing for Eliakim, the Prime Minister for Israel (who had other ministers, paralell to Peter and the other Apostles, though only Eliakim/Peter were given the authority of the keys.) Isaiah 22: (NIV) 20 “In that day I will summon my servant, Eliakim son of Hilkiah. 21 I will clothe him with your robe and fasten your sash around him and hand your authority over to him. He will be a father to those who live in Jerusalem and to the people of Judah. 22 I will place on his shoulder the key to the house of David; what he opens no one can shut, and what he shuts no one can open.
Certainly, Jesus in Matthew 16:18 is establishing Peter as a “rock” of earthly authority (the head of the Apostles and head of the earthly Church) through which Christ will continue to lead His Church. Peter (and his successors, just like Eliakim and his successors and those who went before Eliakim) were instruments of God and were to be visible manifestations of God’s own authority. Jesus, while on earth, was that visible authority. Knowing He would soon ascend back to Haven, he established Peter as the “rock” of authority to be that visible authority which Christians could look to for the solid teachings of Christ; hence Jesus (who is God) gives Peter the “keys of the Kingdom of Heaven” such that (as Jesus Himself says) whatever Peter (or his implied successors) binds on earth will be bound in Heaven, and whatever he looses on earth will be loosed in Heaven. This is an exact parallel of Isaiah 22:22, where Eliakim is given by God the key of the house of David and whatever he opens, none shall shut, whatever he shuts none shall open. Both passages refer to an authority which God is giving to men so that HE cvan rule through these men over his people. God is the eternal rock ruling through the visible rock of authority on earth.
As human beings, we are sensory people. We have 5 senses. That is one reason wy God became visible, took on a human body, so that we could actually SEE Him and touch Him and hear Him in the flesh. Jesus knows the needs of men and women to have a visible authority to turn to with questions and who can lead them in faith (hence why every church has a pastor who is the leader of that community, all the while understanding that Christ Himself is to be the true, eternal authority acting through that pastor’s authority) Peter, and his successors (the Bishop of Rome, today we simply call him the Pope) are merely the visible, human authority over the worldwide Church just like every individual Church community has its own visible, human leader. The early Church had the Apostles to turn to and those Aposstles went out and established churches, and then established Bishops to be their successors when they were gone (like Timothy being established as a Bishop by Paul). The head of all of the Apostles and all of the churches collectively was Peter (as is seen in Acts, and throughout the Gospels with the special way Jesus treats Peter, particularly in giving him the keys of the Kingdom)
Peter was given authority by Jesus to be the visble leader(and likewise Peter’s successors in Rome where Peter died) The Holy Spirit, who descended on Peter and the Apostles at Pentecost, works through the Apostles and their successors worldwide to lead the Church and teach the Apostolic faith given to us by Christ 2000 years ago. The Catholic Church is the only church that maintains this Biblical model throughout the world and is the only authority on earth to properly interpret the Scriptures because it is Christ and the Holy Spirit working through the Bishops, the successors of the Apostles, in their teaching. In the Apostolic age, if you had a question, you asked an Apostle! If you had a question about the Scriptures, you asked an Apostle! Today, if we have questions about the faith or about the Scriptures, who can WE (who are in a world of far greater confusion than the ancients) turn to for an authoritative, true answer which reflects the mind of Christ and the teaching of the Apostles? We ask the Apostles successors, the Bishops of the Catholic Church.**