And THE BIBLE shows clearly that Peter used those keys to open the New Covenant doorway to Jews and Gentiles, albeit he had to have a nudge or two to go to the house of Cornelius. Peter loosed the entry to Heaven and bound the doorway to the following law of sin and death which Jesus covered with His perfect blood.
There are three important biblical images that come together to support the Catholic Church’s claims to papal authority.
The three images are rock, steward, and shepherd. These three images are found not just in one verse, but are rooted in the Old Testament and affirmed in the New. Like a strong, three-strand, braided rope, these three images of rock, steward, and shepherd provide a powerful interlocking and interdependent support for the authority Christ intended to leave with his Church on earth.
So the king holds the keys of the kingdom, but he delegates his power to the steward, and the keys of the kingdom are the symbol of this delegated authority. The keys not only opened all the doors, but they provided access to the store-houses and financial resources of the king. In addition, the keys of the kingdom were worn on a sash that was a ceremonial badge of office.
The passage from Isaiah 22: 21-22 and the customs all reveal that the role of the royal steward was an office given by the king, and that it was a successive office—the keys being handed to the next steward as a sign of the continuing delegated authority of the king himself