On the next day, the multitude that stood on the other side of the sea saw that there was no other boat there, except the one in which his disciples had embarked, and that Jesus hadn't entered with his disciples into the boat, but his disciples had gone away alone.

 6:66-71 After this many of his disciples turned back and would not walk with him any more. Jesus said to the Twelve: "Surely you too do not want to go away?" Simon Peter answered him: "Lord, to whom are we to go? You have the words of eternal life; and we have believed and we have come to know that you are the Holy One of God." Jesus answered them: "Did I not choose you twelve, and one of you is a devil?" He meant Judas, the son of Simon Iscariot, for he was going to betray him--and he was one of the Twelve. 