It is common knowledge that it is those who differ from the norm who are called upon to explain themselves rather than the opposite. That means that if everybody is standing in a line, the person who leaves the line must explain why he did so, rather than those who are in line explain why they are there. In that sense, the onus falls on Christians to explain their faith to us and set out why Jesus was the messiah, as opposed to the Jewish people having to defend themselves against their accusations. On what right did Christians create a new standard for messiahood, virtually ignoring the requirements set down by the Prophets of Israel? It is not the Jew who keeps the time-hallowed traditions and ways of his ancestors whose faith must be on trial, but it is the upstart apostate who must demonstrate to us why he has chosen to reject the ancient path.
On the Shabbat of August 4th, 1263, the Ramban (Nachmanides) was summoned by the Spanish King James to a great disputation at Barcelon between him and the apostate and traitor Paoli Christiani. The subject was the Jews' refusal to accept Christianity. After a few introductody statements, the Ramban arose and spoke clearly and forcefully: "I am amazed. The words said in our presence to convince us that the Nazarene is the Messiah, were said by the Nazarene himself when he brought this same message to our ancestors and tried to persuade them. They refuted him to his face with a perfect and strong rejection despite the fact that it was he who spoke, who knew and could argue his claim that he is divine, in accordance to your opinion, better than you can today. Now, if our ancestors who saw him and knew him did not heed him, how then can we believe and heed the voice of the king, whose only knowledge of the matter stems merely from the hearsay of distant reporters who heard it from people who neither knew him nor were his countrymen as our ancestors knew him and witnessed his life." This, calmly and honestly, is the crux of the matter. Jesus, if he existed as a historical figure as portrayed in the Gospels, certainly presented himself before the Sanhedrin and the greatest of the Sages of the day and argued for his divinity. Jesus was certainly able to argue more passionately and logically for his divinity and messiahood that anybody else can today, and yet they refuted him to his face. In fact, the Jews were so apathetic about him that they found it unecessary to even preserve one Hebrew manuscript of the Gospel as part of the Tanach. They had recognized the falsity of his claim, that the law of Moses was eternal and that the G-d of Abraham, Isaac and Jacob was no pitiful man.
The Jewish conception of G-d is not based upon philosophical reasoning or anceitn dogma. Rather, our knowledge of G-d comes from the mass revelation at Sinai, from our true and goodly prophets and from G-d's mouth Himself. At Sinai, the Jewish people heard G-d proclaim that there is no other besides Him. They were commanded to preserve the memory of that awesome moment and to teach it to their children. "To you it was demonstrated in order that you know that the Lord is the G-d, there is none beside Him." G-d instructed us how to worship Him, and anything which G-d did not tell us to worship in simple terms is idolatry. G-d identified the idols by saying “that which I have not commanded” or “those which you do not know.” Therefore, any deity which G-d has no commanded us to worship or which did not appear to us at Sinai is idolatry. Since no one would argue that Jesus took the Jews out of Egypt, and his name does not appear once in the entire Torah, then by what right does any Jew have to accord him the right of divinity?
The Jewish method of worship has been determined by G-d since Sinai and there is no reason to alter it. When Jesus came before the greatest and most knowledgeable of Sages to preach his new philosophy, they quickly refuted his arguments and prevented him from leading Israel astray. The Jews quickly forgot about this whole event. The early Christian writer Justin quoted a Jew named Trypho as saying: "Ye follow an empty rumour and make a christ for yourself. If he [Jesus] was born and lived somewhere, he is entirely unknown." The Jews responded apahtetically to but another messianic pretender and heretical religious offshoot. Now, if the Jews of Jesus' day saw him face to face, heard his reasoning and arguments from his very mouth, and still knew that he was not the messiah, then why should anybody accept him today when the only thing that is known about Jesus is mere hearsay passed down and distorted through the centuries? What right does a Jew have to disobey and go contrary to the generations of rabbis and sages, indeed the masses of the Jewish people, who were adamant that Jesus was not the messiah but a sinner and a heretic? Why should he break the chain of generations? Is he greater than Rashi and the Rambam, the Ramban and the Vilna Gaon, the Baal Shem Tov among the thousands of great Jewish leaders?