John 6:57-63

57As the living Father sent me, and I live because of the Father; so he that eateth me, he also shall live because of me. 58This is the bread which came down out of heaven: not as the fathers ate, and died; he that eateth this bread shall live for ever. 59These things said he in the synagogue, as he taught in Capernaum.

60Many therefore of his disciples, when they heardthis, said, This is a hard saying; who can hear it? 61But Jesus knowing in himself that his disciples murmured at this, said unto them, Doth this cause you to stumble? 62What then if ye should behold the Son of man ascending where he was before? 63It is the spirit that giveth life; the flesh profiteth nothing: the words that I have spoken unto you are spirit, and are life.