Sunday’s scriptures rely on the sturdiness of rocks as a metaphor for our faith. In Isaiah the people are advised to look to their spiritual ancestors as the rock from which they were hewn. In the Gospel, Jesus declares that the church will be built on the rock of Peter’s bold confession. Like the ancient rock-hewn church of Ethiopia, disciples are formed over time—shaped by learning, worship, and community. As it was for Peter, part of our formation is learning to confess Jesus as the Messiah, not only with the right words but also through an experience of the living God in Christ. Peter’s confession is not a precondition for following Jesus; it comes in the middle of his journey of discipleship. Our formation too is a long process—lifelong, in fact—which begins at baptism (and even before!) and is guided by those who travel before and with us. As Isaiah entreats us, “Look to the rock from which you were hewn,” we can see our faith as the rock of ages.