John 6:51 I am the living bread which came down from heaven: if any man eat of this bread, he shall live for ever: and the bread that I will give is my flesh, which I will give for the life of the world.
Here is the difference between belief and faith.
Jesus is the bread of life and I believe in Jesus. See, here, I can show you, He is right here in my lunch box. I can take the bread and prove to you I have it. See this is my belief.
Jesus is the bread of life and I have faith in Christ. I ate the bread. He nourishes my soul. I am alive because I ate.
John 6:52 The Jews therefore strove among themselves, saying, How can this man give us his flesh to eat?
If you are having a hard time understanding how faith can do this, you are not alone. Many struggle with this very thing. On this issue I must confess I did not understand at first how faith eats because my focus was on eating with my mouth.
Romans 10:9 That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved.
Here once again the word believe is used as faith. Faith consumes the bread of life with the heart. If you take what Jesus said in John 6 and translate it into what Paul is saying in Romans 10 then it would sound like this; I confess I ate the bread of life for I have taken it to heart.
Belief is a mental condition, faith is a spiritual yearning of the heart, a longing for God.
Ezekiel 11:19 And I will give them one heart, and I will put a new spirit within you; and I will take the stony heart out of their flesh, and will give them an heart of flesh: