John 6:53-6:65 for Educated Catholics.

So Jesus said to them, "Truly, truly, I say to you, unless you eat the flesh of the Son of Man and drink his blood, you have no life in you. Whoever feeds on my flesh and drinks my blood has eternal life, and I will raise him up on the last day. For my flesh is true food, and my blood is true drink. Whoever feeds on my flesh and drinks my blood abides in me, and I in him. As the living Father sent me, and I live because of the Father, so whoever feeds on me, he also will live because of me. This is the bread that came down from heaven, not as the fathers ate and died. Whoever feeds on this bread will live forever." Jesus said these things in the synagogue, as he taught at Capernaum.

When many of his disciples heard it, they said, "This is a hard saying; who can listen to it?" But Jesus, knowing in himself that his disciples were grumbling about this, said to them, "Do you take offense at this? That's OK. It doesn't work so well for many of us today. As you indicate in your question, we don't think like Aristotle, nor do we live in a world that lives comfortably with Aristotelian terms. What is most important for you believe, however, is that I am present to you in the church, and in the eucharist, in a way that gives you the spiritual food you need on your life's pilgrimage. "

[Second link via Bill Cork.]