In the Gospel of John, chapter 6, after Jesus had fed over 10,000 men, woman and children by miraculously multiplying 5 barley loaves of bread and two fish, Jesus was with His disciples on the other side of the Sea of Galilee.
The crowd Jesus had fed followed him across the sea to the town of Capernaum. When Jesus saw them He said to them,
“Truly, truly, I say to you, you seek me, not because you saw signs, but because you ate your fill of the loaves. Do not labor for the food which perishes, but for the food which endures to eternal life, which the Son of man will give to you” (John 6:26-27).
Jesus, because He is God, knows our hearts and minds. He knew why the people were following Him. They were not converted by the miracle, they had not come to understand that Jesus was the Messiah, sent from God. Rather, they wanted more free food.
Jesus tells them that they need to stop focusing on material things, and instead focus on spiritual things. This is very often the mistake a well meaning Christian charity will make. They focus so hard on meeting the material needs of the poor, but forget the spiritual needs.
Jesus had said a similar thing to Satan when the demon tempted Jesus in the desert. Satan told Jesus to change a stone into bread, to which Jesus answered, “It is written, “Man shall not live by bread alone, but by every word that proceeds from the mouth of God.” -Matthew 4:4.
Bishop Fulton Sheen, in his masterpiece “The Life of Christ” explained further why providing food alone is not enough:
“The first temptation of Our Blessed Lord was to become a kind of social reformer, and to give bread to the multitudes in the wilderness who could find nothing there but stones. The vision of social [improvement] without spiritual regeneration has constituted a temptation to which many important men in history have succumbed completely. But to Him, this would not be adequate service of the Father; there are deeper needs in man than crushed wheat; and there are greater joys than the full stomach.”
Indeed, to these people who came to Jesus in Capernaum, Jesus was talking about the greatest of joys – the Holy Eucharist. Jesus said to them:
“This is the work of God, that you believe in him whom he has sent… Truly, truly, I say to you, it was not Moses who gave you the bread from heaven; my Father gives you the true bread from heaven. For the bread of God is that which comes down from heaven, and gives life to the world… I am the bread of life; he who comes to me shall not hunger, and he who believes in me shall never thirst.” -John 6:29, 32-33,35