The current papacy is actually an extension of the old Roman Empire. The bishops of Rome took over the administration of the church using the governing methods of the Romans. As the Empire fell, that government became the curia (governing body) of the Catholic church. The pope is the "Pontiflex Maxiums," a Roman term meaning "great bridge." That title goes way back, to the high priests of the old Roman religion.
The Catholic position of pope all started because of a sentence in the gospels that Jesus probably didn't actually say, and even if he DID say it, I think the real meaning has been totally lost amidst all the papal pomp.
Simon was Jesus' favorite apostle. In John 1:42, he tells him, "You are Simon, the son of John. From now on your name is Cephas" (that is, Peter, meaning "a rock").
Jesus goes even further in Matthew 16:17-20, and this is the relevant statement: “Simon, son of Jonah, you are a fortunate man indeed! Now I tell you that you are Peter the rock, and it is on this rock that I am going to found my Church, and the powers of death will never prevail against it. I will give you the keys of the kingdom of Heaven; whatever you forbid on earth will be what is forbidden in Heaven and whatever you permit on earth will be what is permitted in Heaven!”
Since the words "Peter" and "rock" were the same in those days, this is a type of pun: "Peter" as the "rock"--or foundation--of the new church. However, Jesus probably never said these words, because he lived and died a Jew, and had nothing to do with founding Christianity--that was done by Paul after Jesus' death, when he failed to convince the Jewish hierarchy that Jesus had been the Messiah and thus preached this message to the Gentiles (non-Jews living in the area), who then went on to found churches.
Thus all the elaborate trappings of Popedom are based on a single sentence that cannot be authentically attributed to Jesus.
I've always interpreted this statement--which is a lovely one, no matter who said it, very differently than the Catholic church does. But in order to understand my point of view, you need to understand something about Peter--He was completely clueless.
He was foolish and star struck: In Matthew 17:1-4 and Luke 9:28-35, we're told that "Jesus chose Peter, James and his brother John, to accompany him high up on the hill-side where they were quite alone. There his whole appearance changed before their eyes, his face shining like the sun and his clothes as white as light. Then Moses and Elijah were seen talking to Jesus. 'Lord,' exclaimed Peter, “it is wonderful for us to be here! If you like I could put up three shelters, one each for you and Moses and Elijah--' "
But he did not know what he was saying. While he was still talking, a cloud overshadowed them and awe swept over them as it enveloped them. A voice came out of the cloud, saying 'This is my Son, my chosen! Listen to him!'"
He loved his teacher dearly, though. In Mark 14, he tells Jesus, "Even if everyone should lose faith, I never will."
We're told that, "Jesus replied, 'Believe me, Peter, this very night before the cock crows twice, you will disown me three times.'"
Jesus returns after praying and finds his disciples are all fast asleep. He says to Peter, "Are you asleep, Simon? Couldn't you manage to watch for a single hour?"
After Judas came into the room with the soldiers and delivered the betraying kiss, identifying Jesus, the soldiers marched him away Peter followed at a safe distance, and ended up in the high priest's courtyard, where a group of servants were sitting around a fire.
One of the high priest's maids saw him warming himself in front of the fire. She looked closely at him, and said, "You were with the Nazarene too--with Jesus!"
But he denied it, saying, "I don't understand. I don't know what you’re talking about." As he walked out, a rooster (cock) crowed.
But the maid was insistent, and said to some men standing there, "This man is one of them!"
But Peter denied it again. A few minutes later other bystanders said to Peter, "You're certainly are one of them. Why, you're a Galilean!"
He started to curse and swear and said, "I tell you I don’t know the man you're talking about!"
Immediately the cock crowed for the second time, and the prophetic words of Jesus came back into Peter's mind, and he broke down and wept.
It's the same thing most of us would have done in those circumstances--Denied being an associate of someone who was about to be tried as a criminal and most likely put to death, lest the same grisly fate happen to us. Peter, the "rock upon which the Christian church is supposedly built, was not someone special, he was an ordinary, fallible person. What that statement really means--to me, anyway--is that Christianity isn't based on following special leaders, it's based on the ordinary, feckless, not-so-special guy, the "rock" that is always with us, always trying (and failing, and trying again) to live up to the teachings of a great Shaman.