Dantech said:
So if he hasn't completed his job, than how could he be the Messiah.
...I'm not one of the early Christians, but I will try to excavate a possible opinion of theirs. Since the messiah is expected to die then his life's work must continue to provide long after his death. Lets suppose that Malachi 4:2 is messianic. Malachi says that "The law will go out from Zion, the word of the LORD from Jerusalem." If there are multiple generations of people in the world after the messiah has died, then somehow his work must continue even though he has died, and the law must continue to go forth. So at what point can Jews test him in that matter to know whether he's a true prophet?
Ok, now lets look at Deuteronomy 18 using my own perspective on it, so that I may answer your question within the framework that I understand. Even after a prophet has died the Jew is instructed to listen to that prophet's words according to Deuteronomy 18:15, or it would say "You must listen to him but only until he dies." (It doesn't say that.) I think Jews recorded what the prophets told them not only because they valued the prophets but because of this order. Let us say they used the test in Deut. 18:22 to decide which prophets were valid...ok then let us look at the Jews objection to Jesus. It is on the basis that he said "The Kingdom of God is at Hand" among other things; but he made clear that his kingdom was not of his era. In fact he did not make any claims to accomplish anything literally within the time frame of his own life's span. He left it open-ended and prayed that it would be completed. Then it becomes difficult I think for you to say that he didn't accomplish what he promised, because he didn't promise to accomplish it while he was alive. At the same time you don't have to listen to what he said, because it hasn't been accomplished, yet.
Do you know how many Jews, not even 20 years ago were 100% sure that the Lubavitcher Rebbe was the Messiah? They had as much faith as you could imagine. But once the person passes away, and hasn't completed his task. That's it! It's over, he isn't the Messiah. Jews didn't then go on and write a book that they called the New bible to try and render stories and accounts to make people believe that this person will indeed be the Messiah.
I cannot speak to their situation, but if the Lubavitcher Rebbe had established a work that would ultimately result in the fulfillment of messianic prophecies, then the Lubavitcher Rebbe would have accomplished an amazing thing during his lifetime.
People have claimed to be Messiahs in history. Many were believed by some. Some were believed by many. But at some point, you got to face the reality that once he hasn't accomplished his job, that you were wrong. It's okay to be wrong.
It is ok to be wrong, yes.
Ask CMike, I believe he is of the Chabad denomination. Do you know how much the Rebbe Menachem Mendel Schneerson has accomplished in his life? Do you know how many followers he had, and still has after his death? The numbers are only growing and they are doing so exponentially. However no one believes he is the Messiah anymore, because he died and hasn't accomplished the prophecies.
I have no idea how any person could accomplish the wishes of all of the prophets in a single lifetime. To you it may seem possible, and I don't want to discourage you. Carry on!