In the Catholic culture , the Consecration of the Mass is known as the priests´ reinterpretation of Jesus´ Last Supper .
Catholics believe that at the Consecration of the Mass ( when the priest reenacts Jesus ' Last Supper 's saying `` This is my body '' and `` This is my blood '' ) , the substance of the bread and wine is changed into that of Jesus Christ .
Funeral of Pope John Paul II