John 6:66-71 New Revised Standard Version (NRSV)
66 Because of this many of his disciples turned back and no longer went about with him. 67 So Jesus asked the twelve, “Do you also wish to go away?” 68 Simon Peter answered him, “Lord, to whom can we go? You have the words of eternal life. 69 We have come to believe and know that you are the Holy One of God.”[a] 70 Jesus answered them, “Did I not choose you, the twelve? Yet one of you is a devil.” 71 He was speaking of Judas son of Simon Iscariot,[b] for he, though one of the twelve, was going to betray him.