Jesus introduced his disciples to the Eucharist before Last Supper even began. In John 6 when addressing a crowd, he taught, "I am the bread of life... Truly I tell you, unless you eat the flesh of the Son of Man and drink his blood, you have no life in you."
He gave them this teaching in a way that was straightforward and adamant, contrasting his earlier parables. When he got push back, instead of explaining it as a metaphor or symbolism, he doubled down on it, this time using a more precise meaning for the word "eat," -"trogo" which in Greek literally means "to gnaw or chew." Some of the crowd, after hearing this clarification, left, and can you blame them??
I often wonder how I would have handled this teaching, if I too was told I had to chew on a man's flesh...
But the most beautiful part of this entire encounter is Simon Peter. Clearly, looking at how this whole story unfolds, we know Peter is far from perfect. But in this moment, we've got to give him credit. His faith in Jesus was unshakeable.
Jesus says, "Does this offend you? (...) Will you also go away?" Peter answered him, not because he somehow had a supernatural understanding and peace about this teaching, but because he loved Jesus to no end,
“Lord, to whom shall we go? You have the words of eternal life; and we have believed, and have come to know, that you are the Holy One of God.”
How do I respond to the hard teachings of the Church, when the world calls them offensive and unpleasant? Do I abandon Her because I don't fully understand them? Do I let my pride convince me that if my limited comprehension can't fully grasp it, it must be false?
Or do I respond like Peter, who in humility recognizes that there are things of heaven which he will never fully understand while still on earth, but in his love for God, chooses to stay?