Kneeling before the tomb of St. Peter, Pope Francis repeated the three professions of faith the Gospels report the apostle making:
Lord, you are the Christ, the son of the living God;
Master, to whom shall we go? You have the words of eternal life; and
Lord, you know everything; you know I love you.
Cardinal Angelo Comastri, archpriest of St. Peter's Basilica, said Pope Francis made the three professions April 1 while kneeling on the marble floor of the Clementine Chapel, facing a grill that allows visitors to see the back of what is believed to be St. Peter's tomb.
"It was moving for us to hear the pope, who took these words of Peter and made them live again, because today it is his mission to continue the mission Jesus entrusted to Peter," the cardinal told Vatican Radio.
Cardinal Comastri accompanied Pope Francis on a late-afternoon tour of the excavated necropolis where St. Peter is buried. Jesuit Father Federico Lombardi, Vatican spokesman, said Pope Francis was the first pope to tour the site, walking the path between mostly second-century burial vaults to the tomb.
However, they did not approach the tomb in the same way other popes had visited the excavations while the work was under way. Pope Pius XII, who initially authorized the excavations, reportedly rushed down into the necropolis in 1950 when he heard the archaeologists had found some bones. Pope Paul VI, who had announced in 1968 that after almost 20 years of further excavation and study, the relics of St. Peter "have been identified in a manner which we believe convincing," went to the site the next day and led a brief prayer service. The relics were put back near where they were found.
When Pope Francis made his visit, he was accompanied by Cardinal Comastri and the two directors of the necropolis who provided explanations, including by using a tablet computer to illustrate what was found.
Pope Francis walked through the necropolis and went up a slight incline toward the tomb of Peter which is directly under the main altar of St. Peter's Basilica.
In the Clementine Chapel, "the place closest to the tomb of the Prince of the Apostles, the pope paused in silent prayer and in a deep and moving moment of reflection," Father Lombardi said.
Pope Francis spent 45 minutes in the necropolis and in the Vatican grotto where he paid homage at the tombs of several popes, including Popes Benedict XV, Pius XI, Pius XII, Paul VI and John Paul I, Father Lombardi said.
The entrance to the grotto and necropolis is across a parking lot from the Domus Sanctae Marthae where the pope is living. The pope walked there and back, Father Lombardi said.
The necropolis is a burial ground where St. Peter's tomb has been venerated since early Christian times and where the first church dedicated to the saint was built. The tomb is two levels below the main altar of the modern basilica.
On the level between the necropolis and the basilica is the Vatican grotto, the place where many popes and a few Catholic nobles have been buried since the 10th century.
The necropolis was excavated in the 1930s and '40s, which led to discovery of a double row of mausoleums and niches decorated with paintings, stucco and mosaics along with a section of simpler graves.
The archaeologists also discovered a bit of graffiti scrawled on a piece of red-tinted wall dated to sometime shortly before the year 200; it reads "Petros Eni" (Peter is here). Nearby were found the remains of the altar the Emperor Constantine was believed to have ordered erected over St. Peter's tomb in 324.
The bits of human bones found near the red wall and ancient altar were studied for years and became the object of intense debate among Catholic archaeologists until Pope Paul's announcement in 1968 that he was convinced the relics were those of St. Peter.
Since 1998, the Vatican has been repairing and restoring the tombs, labyrinthine lanes and funerary artwork in the necropolis using state-of-the-art techniques. It also set up a complete conservation and lighting system that controls the climate of the necropolis to prevent further damage.