In Christianity, "the keys are an office and power given by Christto the Church for binding and loosing sins." In a non-Christian context, the symbology of the power of keys dates back to the birth of civilization. The common element is that of the gatekeeper of time.
Christianity
The Power of the Keys is a responsibility given to St. Peter to usher in the Kingdom of God on the Day of Pentecost, and a responsibility given to the other Apostles by Christ, according to and. It is understood as a responsibility to admit or exclude from church membership, to set church policy and teachings, to render binding interpretations of Sacred Scripture, and to bind and loose sins. The verb 'to loose' is used this way in John 20:23, Rev 1:5 and by the Early Church Fathers. It is a power that Roman Catholics believe to have been conferred first on St. Peter then afterwards on his successors in the office of the Roman CatholicPapacy. There is a description of the conferral of the Power of the Keys on St. Peter in Matthew 16:13:
13When Jesus went into the region of Caesarea Philippi he asked his disciples, "Who do people say that the Son of Man is?" 14 They replied, "Some say John the Baptist, 15 others Elijah, still others Jeremiah or one of the prophets."15 He said to them, "But who do you say that I am?" 16Simon Peter said in reply, "You are the Messiah, the Son of the living God." 17 Jesus said to him in reply, "Blessed are you, Simon son of Jonah. For flesh and blood has not revealed this to you, but my heavenly Father. 18 And so I say to you, you are Peter, and upon this rock I will build my church, and the gates of the netherworld shall not prevail against it. 19 I will give you the keys to the kingdom of heaven. Whatever you bind on earth shall be bound in heaven; and whatever you loose on earth shall be loosed in heaven."
In Matthew chapter 18, 18 through 20, we see Jesus speaking to the disciples, not an individual specifically. This points to Jesus continuing to instruct the disciples in chapter 16, and perhaps not Peter individually after blessing Peter for having confessed who Jesus was by God's allowance; This point of view is furthered in the first Council of Jerusalem. Roman Catholic dogma states that in Matthew 16, Jesus was paraphrasing a passage from Isaiah well known among the Jews in which Hezekiah, the King of Israel, had a general cabinet of ministers and his chief chamberlain, the Prime Minister Shebna was proved unworthy of his post and was thrown out. To fill his office, King Hezekiah names Eliakim son of Hilkiah as the new prime minister:
15 Thus says the Lord, the GOD of hosts: Up, go to that official, Shebna, master of the palace, 16 Who has hewn for himself a sepulcher on a height and carved his tomb in the rock: "What are you doing here, and what people have you here, that here you have hewn for yourself a tomb?" 17 The LORD shall hurl you down headlong, mortal man! He shall grip you firmly 18 And roll you up and toss you like a ball into an open land To perish there, you and the chariots you glory in, you disgrace to your master's house! 19 I will thrust you from your office and pull you down from your station. 20 On that day I will summon my servant Eliakim, son of Hilkiah; 21 I will clothe him with your robe, and gird him with your sash, and give over to him your authority. He shall be a father to the inhabitants of Jerusalem, and to the house of Judah. 22 I will place the key of the House of David on his shoulder; when he opens, no one shall shut, when he shuts, no one shall open. 23 I will fix him like a peg in a sure spot, to be a place of honor for his family;
In the Bible, the term "keys" has been used as a symbol of teaching authority. According to Roman Catholics, Jesus, the son of David and hence the King of the new Davidic kingdom, the Church, appoints St. Peter as the Church's primary teacher, an office that will continue to have successors much like Eliakim's position in the Old Testament Davidic kingdom. With these keys, like Eliakim, St. Peter the first Bishop of Rome and his successors are entrusted with Christ's own teaching authority over the new House of David, the Church here on earth. Through this office of the Papacy and the Magisterium, Roman Catholics believe that the Kingdom of Heaven governs the Church on earth to lead it to all truth in matters of faith and morals. Many Christians point out that Jesus uses much the same language in John 20:23 and therefore conferred some or all of the same powers on all the Apostles. On this basis, Eastern Orthodox believe that the power of the keys is conferred on all bishops. Similarly, Martin Luther and other reformers spoke of the "office of the Keys" as the power of church leaders to admit or exclude from church membership. The Vatican's own claims to the Keys as a heraldic statement are limited to the 14th century.