The Mass of Saint Gregory the Great, about 1510-1550. Additional Info: While performing mass one day, Pope Gregory became aware of a disbeliever in the congregation and prayed for a sign that would leave no doubt about the real presence of Christ in the Mass. Christ materialized above the altar as the Man of Sorrows, displaying the stigmata and surrounded by the instruments and symbols of his Passion. The first amongst the celebrants to perceive the vision, Gregory kneels in reverence and gazes up intently, hands spread, while those around him remain as yet unaware of the miracle.