18 The scholastic Doctors made similar statements on more than one occasion. As St. Thomas says, the fact that the true body and the true blood of Christ are present in this Sacrament "cannot be apprehended by the senses but only by faith, which rests upon divine authority. This is why Cyril comments upon the words, This is my body which is delivered up for you , in Luke 22, 19, in this way: Do not doubt that this is true; instead accept the words of the Savior in faith; for since He is truth, He cannot tell a lie." (6)
Source: Mysterium Fidei (Vatican.va)