That originated when Jesus Christ himself said that, "Blessed are you, Simon Barionah (Peter son of Jonah). For flesh and blood has not revealed this to your, but my heavenly Father....I will give you the KEYS TO THE KINGDOM OF HEAVEN...."
You can find the verses above on chapter 16 from the Gospel according to Matthew in the Holy Bible. The verses quoted above is from verse 17 and 19
Answer Peter is also known as "The Rock of Christianity" and he is the leader of the Christian Church.
In The Bible, Jesus gives St. Peter the keys to the kingdom of heaven as a symbol of his authority to lead the early Christian church. This act signifies Peter as the foundation upon which the church would be built, granting him a leadership role among the apostles.
Because in St. Matthew's Gospel, chapter 16, verses 17-19 where Our Blessed Lord is appointing him the Vicar of His Church, he uses the imaginary of from the last part of the 22nd chapter of Isaiah where the Lord gives Eliacim the "keys of the kingdom", which Our Blessed Lord gives to St. Peter and his successors.
Peter, the first pope, is usually represented by two keys - the keys to the kingdom of heaven symbolically given to him by Christ.
The keys to the Kingdom of Heaven.
This power was given to St. Peter to symbolize the authority he would have to access the kingdom of heaven.
In Christian tradition, St. Peter is often depicted holding keys as a symbol of his role as the keeper of the keys to heaven. This imagery is based on a passage in the Bible where Jesus gives Peter the keys to the kingdom of heaven, granting him the authority to govern the church on earth.
The keys of St. Patrick symbolize the power of spiritual authority and the responsibility to guide and protect the faith. According to legend, St. Patrick was given the keys to heaven as a sign of his role as a spiritual leader and protector of the Christian faith in Ireland. The keys are often depicted in art and imagery associated with St. Patrick as a symbol of his significance in the Christian tradition.
St. Peter is given the "keys to the kingdom of Heaven" by Jesus, which symbolizes his authority as the leader of the Christian church. This is referenced in the Bible in the Gospel of Matthew 16:18-19.
St Peter is usually depicted holding keys (the keys of heaven). Or, sometimes he is depicted being crucified upside down (as it seems to have been St Peter's wishes when he too was crucified).
Jesus says to St. Peter--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." --Matthew 16:19 New American Standard Bible
There is no specific saint known for waiting at the door of heaven. In Christian tradition, Saint Peter is often depicted as the gatekeeper of heaven, with the keys to the kingdom.
The Pope holds the "Keys to the Kingdom of Heaven" according to scripture. These "keys" were first given to St. Peter by Jesus Christ (Matthew 16:15-19). It is the understanding of the Church that these keys are then passed on to his Successors in his post as head of the Church. For a more learned discussion on this topic you may want to consult these two pages: http://www.catholic.com/library/Peter_the_Rock.asp http://www.catholic.com/library/Origins_of_Peter_as_Pope.asp
The name is attributed to the belief that just as St Peter holds the keys to heaven
When Our Lord told Peter, "I will give to thee the keys of the kingdom of Heaven. Whatever you bind on earth shall be bound also in Heaven. Whatever you loose on earth shall also be loosed in Heaven."