If you look again at what Pope Benedict stated above you would see that our understanding of the role of Peter is based on more than this one text. Moreover, as Catholics we look beyond the Bible to the Sacred Tradition of the Church, of which the Bible is a product.
We are all filled with, and guided by the Holy Spirit 'when' we asked Jesus to save us from our sins...Nothing more, nothing less...And as such, we are members of His church...The Bride of Christ...
Then how do you explain that we have such different ideas about the faith for I pray everyday to be forgiven by Jesus of my sins and to be guided by the Holy Spirit?
Actually, I'm not so sure we have different ideas about "faith." We have differences in our ideas about worship, religious practice, and sacraments. I think we agree very well on faith, God, and Jesus Christ, and his Word.
I could be mistaken, and since I am such an infant Christian I could be very wrong about my above assumptions, but I don't think so.