“Material food first of all turns itself into the person who eats it, and as a consequence, restores his losses and increases his vital energies. Spiritual food, on the other hand, turns the person who eats it into Itself, and thus the proper effect of this sacrament is the conversion of man into Christ, so that he may no longer live for himself, but that Christ may live in Him. And as a consequence it has the double effect of restoring the spiritual losses caused by sins and defects and of increasing the power of the virtues.”

~St. Thomas Aquinas