On the next day the crowd that remained on the other side of the sea saw that there had been only one boat there, and that Jesus had not entered the boat with His disciples, but that His disciples had gone away alone. Other boats from Tiberias came near the place where they had eaten the bread after the Lord had given thanks. So when the crowd saw that Jesus was not there, nor His disciples, they themselves got into the boats and went to Capernaum, seeking Jesus.
When they found Him on the other side of the sea, they said to Him, “Rabbi, when did you come here?”
Jesus answered them, “Truly truly I say to you, you are seeking me, not because you saw signs, but because you ate your fill of the loaves. Do not labor for the food that perishes, but for the food that endures to eternal life, which the Son of Man will give to you. For on Him God the Father has set His seal.”
Then they said to Him, “What must we do, to be doing the works of God?”
Jesus answered them, “This is the work of God, that you believe in Him whom He has sent.”
So they said to Him, “Then what sign will you do, that we may see and believe you? What work do you perform? Our fathers ate manna in the wilderness; as it is written, ‘He gave them bread from heaven to eat.'”
Jesus said to them, “I Am the Bread of Life; whoever comes to me shall not hunger, and whoever believes in me shall never thirst….”
“…Whoever feeds on my body and drinks my blood has eternal life, and I will raise him 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 will also live because of me. This is the bread that came down from heaven, not like the bread the fathers ate and died. Whoever feeds on this bread will live forever.”
– John 6:22-35, 54-58
How can bodily eating and drinking do such great things…?