When a priest pronounces the words of Eucharistic consecration at Mass, the bread and wine, by the power of the Holy Spirit, are changed into the Body and Blood of Christ, which were given for us in sacrifice. At the Last Supper, Jesus’ words and power made Him really and substantially present under the outward appearances of bread and wine …

Our Lord Jesus Himself, true God and true man, is really and substantially present, in a mysterious way, under the appearances of bread and wine. After the priest speaks the words of consecration, the appearances of bread and wine remain, meaning that bread and wine appear to be there but are not really there substantially. At the Last Supper, when …