Jesus explains that his Church will be invincible, because it too will be founded on rock, the rock of Peter, whose special role is guaranteed by “my heavenly Father.” 

Peter will receive the authority to rule that Church in Christ’s name. This authority is symbolized by the keys and the “binding and loosing”: the former refers to authority held in ancient Israel by the King’s master of the palace (cf. Is 22:22]; the latter refers to the authority of the Jewish synagogue leader to expel and reinstate people from the synagogue community, in order to preserve the community’s religious and moral integrity. 

This authority has remained intact through twenty centuries of popes (the successors of St Peter as Vicars of Christ on earth), giving the Catholic Church unity of faith, worship, and governance in spite of its members’ many failings. Christ had the authority; he demonstrated it over and over again. 

He gave it to Peter – he didn’t have to, but he wanted to spread his Kingdom through a Church that was both human and divine, just as he wanted to redeem us through the two natures (human and divine) of the Incarnation. We may find God’s strategy hard to understand (why didn’t Christ himself just stick around after his resurrection and rule the Church?) but we cannot deny it.

There is one Lord: Jesus Christ. And he founded one Church to wage his definitive war against sin and evil: that Church’s keys are in Peter’s hands.

We can count on Christ. He promises that the gates of the underworld (the gates of hell, the powers of the devil) will not prevail against the ferocious assaults of his Church. In other words, his team will win; his Kingdom will stand – both in our hearts and in the world. If we follow Christ, if we stay faithful to him, we will share in his victory; we can count on it. The history of the Church confirms it. Scandals, heresies, wars, slander, and seduction have all tried to halt her advance – to no avail. In every age her voice rings out in defense of human freedom and the truth of Jesus Christ. In every epoch she renews the human race with saints whose divine love sets the world ablaze. In every era she widens the scope of her saving action. We can count on Christ, but can he count on us?

Jesus: I knew that you would need a firm point of reference as you travel through life. I knew that you would need a rock to hang on to when fashionable trends and apparently reasonable cultural options tried to sweep you away. This is why I left you my vicar on earth, the pope. Follow his teaching, because it is my teaching. Listen to him, because I want to guide you through him. If I hadn’t left you a guide, you would be at the mercy of flippant fads. I want you to grow in wisdom and grace steadily, without interruptions, without going down dead-end detours, without suffering the damage inflicted by false philosophies and distorted theologies. Stay close to me, stay close to my vicar; I won’t lead you astray”