When Jesus went into the region of Caesarea Philippi he asked his disciples, "Who do people say that the Son of Man is?" They replied, "Some say John the Baptist, others Elijah, still others Jeremiah or one of the prophets." He said to them, "But who do you say that I am?" Simon Peter said in reply, "You are the Christ, the Son of the living God." 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. 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. 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." Matthew 16:13-19
It took guts for Simon Peter to call Jesus "the Christ" and "the Son of the Living God." When you said stuff like that publicly, you could be killed back then. But Jesus rewarded Simon Peter by telling him that he will be the rock that His Church will be built on.
I read an article in the Catholic Women's Devotional Bible (NRSV) by Louise Perrotta. She talks about keys being the symbol of power (ask any teenager!). "Peter's keys signify a supreme authority to govern God's house, the Church."
She also talks about "Jesus' amazing promise made to all 12 apostles to "bind or loose" in heaven - to back up with His own authority - whatever they "bind or loose" on earth. In union with Peter, the Church's main shepherd on earth, the Eleven have divine backing for the authority they, too, are called to exercise."
But the part of the article I liked best was Louise Perrotta's insights about "God's dealings with us:"
"Peter's special commissioning reveals the divine willingness to takes risks. Impetuous, inconstant, and slow to understand, Peter, would not have been a modern headhunter's first choice for a CEO. Yet Peter is the apostle that Jesus commissioned to be his chief personal representative. "Strengthen your brothers," he charged him. "feed my sheep" (Luke 22:32; John 21:17). Filled with the Spirit at Pentecost, Peter rose to the challenge."
We have had many popes since Peter. Some were very good and some were not. The Church has survived despite them.
I think we forget that we are also stepping stones to the rock. The leaders of our Church may falter, but the faith of its people will carry the Church to its future.