St. Augustine of Hippo Muses on the Sacraments

iuYour Lord is seated at the Father’s right hand in heaven. How then is the bread His Body? And the chalice, or rather its content, how is it His Blood?

These elements are called Sacraments, because in them one thing is perceived by the senses and another thing by the mind. What is seen has bodily appearance; what the mind perceives produces spiritual fruit. You hear the words “The Body of Christ,” and you answer “Amen” [so be it].

—Augustine of Hippo, Sermon 272.