I agree that there is no explanation why someone who wandered Galilee with Jesus and is followers would turn on him. Obviously, Judas did not believe that Jesus was the Messiah – betraying the anointed one would have been suicidal. One explanation may be that Jesus’ personal belief of his divinity was something that was evolving in his divinity and Judas and perhaps other inner circle members did not see Jesus fulfilling the Messianic prophesies. The reaction was to betray him to get him expelled from Jerusalem and thereby allow Jesus to return to his ministry in the backwater of Galilee. It’s hard to believe that Jesus could have claimed his divinity to the Jews in Sephora or other populated communities in Galilee without scrutiny of the local Jewish hierarchy. The passages about the locals and his family thinking that he was having mental problems says more about the reaction from local Jews. Traveling to Jerusalem; the Messianic entrance and the disruption at the Temple may have triggered a response from one or more of his disciples to “save him from himself”. It also may explain the seeming disappearance of most of the disciples from the religions history.