One aspect that the great reformer, the Rev. Dr. Martin Luther, found to be problematic within the Roman Catholic Church was the sacrifice of the Mass and what is called Transubstantiation which is meant that as the Priest was saying to words of Institution, Christ's words at the Last Supper, "this is my body...this is my blood," through the saying of these words by the priest and the actions of the priest would change the bread and the wine into flesh and blood. Luther did not have issue with the fact that the bread and wine would be revealed as Christ's body and blood through the words, but that it was through the action of the priest and what was known as the Sacrifice of the Mass which was a re-sacrifice of Christ each and every time the mass would be celebrated. Luther believed and we see to be true within Scripture that the words that Christ says, "this is my body...this is my blood," are to be trusted not because of the Priest but because of Christ and the miracle that Jesus is in, with, and under the bread and the wine and they are his body and blood, not a change that happens in the Roman Catholic rite but they are both his body and blood and bread and wine simultaneously. They do not represent, but they are. The reality of what they are is not based on us, but on Christ's words and promise and with them we receive what Christ promises, "the forgiveness of sins."