Twelfth Ikkar of the Rambam
The Twelfth Ikkar (fundamental Torah principle) of the Rambam's Thirteen Ikkarim:
"Principle XII. The era of the Messiah And this is to believe that in truth that he will come and that you should be waiting for him even though he delays in coming. And you should not calculate times for him to come, or to look in the verses of Tanach to see when he should come. The sages say: The wisdom of those who calculate times [of his coming] is small and that you should believe that he will be greater and more honored than all of the kings of Israel since the beginning of time as it is prophesied by all the prophets from Moses our teacher, peace be upon him, until Malachi, peace be upon him. And he who doubts or diminishes the greatness of the Messiah is a denier in all the Torah for it testifies to the Messiah explicitly in the portion of Bilam and the portion of “You are gathered (towards the end of Deut)”. And part of this principle that there is no king of Israel except from the house of David and from the seed of Solomon alone. And anyone who disputes this regarding this family is a denier of the name of God and in all the words of the prophets. "
The true Moshiach will be identified by everyone due to his status as a great living Jewish king. If a Jewish person is not such a living king, he cannot be Moshiach.
Recently I was involved in a debate with a Chabad Meshichist on Facebook who was trying to convince me that "Moshiach could be from the dead".
It is essential that we not be deceived by deceptive arguments, such as "Moshiach could be from the dead", that ignore what Moshiach's status will be when he arrives. Such arguments are being used by persons with agendas to convert Jews to false ideologies.
I believe it is important for non-Chabad Jews to understand the fundamental principles of Moshiach, so as not to be mislead by aggressive missionaries (Jewish or non-Jewish) who are promoting what are essentially different religions than Judaism.
False messiahs have caused enormous damage throughout Jewish history. The present era seems to be repeating events that occurred in the Jewish world about 2000 years ago.
The link below contains a summary of the scholarly Torah sefer "False Messiahs and their Opponents" that was published by senior rabbinic scholars in Israel.
"When the true Mashiach is revealed, there will be no possible doubt about his identity. The entire world will be forced to recognise him."