John 6:51 (NIV) "I am the living bread that came down from heaven. If anyone eats of this bread, he will live forever. This bread is my flesh, which I will give for the life of the world."
Have you ever eaten bread that was alive? Well, of course not, so how is this statement Jesus is making a sensible one? In relation to the natural things in life, it is not. Bread is not a living organism. The wheat that once was living and produced the grain the bread is made from is long departed. We can't understand spiritual things with carnal thinking, we must tap into the spiritual concept that Jesus is revealing.
Jesus is making the analogy with bread being a life sustaining food for our physical bodies and He, being a spiritual bread, a sustenance for our spirit. This is the scripture we use with taking communion, the ritual of remembering the sacrifice of Jesus' body and blood on the cross.
In the Old Testament, God gave the children of Israel manna that fell with the dew upon the ground. It was like a seed or a grain that they would gather in the mornings, grind it and make it into bread. It was a supernatural type bread, in that it sustained them. You could say that it was bread from heaven. This is a type and shadow of Jesus, the bread from heaven that was yet to come. The manna would not last from one day to the next. It could not be saved and used later because it would spoil. It was bread for the day it was gathered and that day alone.
Lamentations 3:22-23 (NLT) "The faithful love of the Lord never ends! His mercies never cease. Great is his faithfulness; his mercies begin afresh each morning."
We can't live on yesterday's manna, but must gather the fresh nourishment of Jesus for that day. He is current, He is now, He is with us, He is bread to our soul, He is the sustenance needed to trek through the desert of life, journeying to our land of great promise.