One of the most important doctrinal changes made by Protestants involved the reinterpretation of the Latin words hoc est corpus meum which are found in the institution of the Lord’s Supper in Matthew 26:26 of the Catholic Bible, the Vulgate. The English translation of what Jesus said to his disciples is “this is my body.” The words Jesus pronounced that evening were few, but by the sixteenth century they had been interpreted into the Mass which is the traditional Catholic word for the Eucharist or Lord’s Supper liturgy. As the Reformers studied Scripture with a critical eye to the Mass it became clear to them that it was based on flawed theology that had been influenced significantly by Medieval philosophy and logic.
In the Mass, Catholicism interpreted “this is my body” in a literal way so that even though the bread and wine continue to appear as such physically, they are in fact in substance the body and blood of Jesus. How does common bread and wine become the Lord’s true body and blood? When the priest pronounces the words of institution given by Jesus, he is, in fact, acting in the person of Christ to consecrate the bread and wine so that they change through transubstantiation into the Lord’s body and blood. Further, the Mass was said to be a sacrifice for sin.
So, if the practice of the Mass was believed to be incorrect, what were the Reformers going to put in its place in the light of sola Scriptura?