At the point at which John Paul II began his papacy in the first volume of my biography of him, Witness to Hope, I borrowed some thoughts from Hans Urs von Balthasar and tried to explain a bit of the uniqueness of the papal office:
An impossible task
“To be pope is to take on a task that is, by precise theological definition, impossible. Like every other office in the Church, the papacy exists for the sake of holiness. The office, though, is a creature of time and space, and holiness is eternal. No one, not even a pope who is a saint, can fully satisfy the office’s demands.