And I tell you that you are Peter, and on this rock I will build my church, and the gates of Hades will not overcome it. I will give you the keys of the kingdom of heaven; whatever you bind on earth will be bound in heaven, and whatever you loose on earth will be loosed in heaven.
The above verses are Matthew 16, verses 18 and 19. This has always been the classical proof text for the Catholic view of the Papacy. St. Peter was the first bishop of Rome and therefore his successors carry authority granted to no other bishop.