“Many therefore of his disciples, when they had heard this, said, This is an hard saying; who can hear it? When Jesus knew in himself that his disciples murmured at it, he said to them, ‘Does this offend you? What and if you shall see the Son of man ascend up where he was before? It is the spirit that vivifies; the flesh profits nothing: the words that I speak to you, they are spirit, and they are life. But there are some of you that believe not.’ For Jesus knew from the beginning who they were that believed not, and who should betray him. And he said, Therefore said I to you, that no man can come to me, except it were given to him of my Father.’ From that time many of his disciples went back, and walked no more with him. Then said Jesus to the twelve, ‘Will you also go away?’ Then Simon Peter answered him, ‘Lord, to whom shall we go? you have the words of eternal life. And we believe and are sure that you are that Christ, the Son of the living God.’ Jesus answered them, Have not I chosen you twelve, and one of you is a devil?’ He spoke of Judas Iscariot the son of Simon: for he it was that should betray him, being one of the twelve.”
(John 6:60-71 American KJV)