John 6:60-63

60Many therefore of his disciples, when they heard this, 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 quickeneth; the flesh profiteth nothing: the words that I have spoken unto you are spirit, and are life.