John 6:64-71

But [still] there are some of you who do not believe and have faith.” For Jesus knew from the beginning who did not believe, and who would betray Him. And He was saying, “This is the reason why I have told you that no one can come to Me unless it has been granted him [that is, unless he is enabled to do so] by the Father.” As a result of this many of His disciples abandoned Him, and no longer walked with Him. So Jesus said to the twelve [disciples], “You do not want to leave too, do you?” Simon Peter answered, “Lord, to whom shall we go? You [alone] have the words of eternal life [you are our only hope]. We have believed and confidently trusted, and [even more] we have come to know [by personal observation and experience] that You are the Holy One of God [the Christ, the Son of the living God].” Jesus answered them, “Did I not choose you, the twelve [disciples]? And yet one of you is a devil (ally of Satan).” Now He was speaking of Judas, the son of Simon Iscariot; for he, one of the twelve [disciples], was about to betray Him.