Catholics believe that the Holy Eucharist that they receive at Mass is the body and blood of Christ — not just a reenactment or a symbol, but the true substance of Jesus Christ, only with the visual appearance, taste, smell, etc., of bread. In other words, we believe that when Jesus said, “This is my Body,” he meant it literally. And then, when he said, “Do this in memory of me,” he also meant that literally. So to this day, we do it at every Mass.