1) The Arizal, one of the most important Kabbalists who lived 400 years ago, writes in his book, Sha'ar HaGilgulim (chapter 13), that Moshiach does not die. After Moshiach reveals himself, there is a period of concealment, and then he is revealed again.
2) Yaakov our Father did not die. Rashi says that Yaakov our Father did not die; it just seemed to the people as if he had died. Even though the Egyptians embalmed and buried him, Torah asserts that he lives spiritually and physically. Therefore, the Torah teaches us that although our physical eyes may tell us one thing, the Torah establishes what the true reality is.
3) The leader of the generation, like the Even HaShesiya (Foundation Stone of the world and the Holy Temple), exists eternally in the physical world and is not subject to burial (geniza). In 5751 (1991), the Rebbe said the following:
"And in the most general sense, the entire world becomes a private domain saturated with the singular essence of the 'Lone Master of the World.' The way He reveals Himself in the world through His prophet whom He anoints, since the 'Nasi is everything' and 'the tzaddik is the foundation of the world. This phenomenon (of 'the tzaddik...') can be compared to the Even HaShesiya. This age-old rock exists eternally in this physical world, and is not subject to any sort of variation, not even the variation of being stored away like the Holy Ark, which was stored away. The same is true with regard to the judge and prophet of the generation. A judge and prophet must exist perpetually in every generation as a sign of Hashem's constant manifestation in the world, that from Him is derived the existence of the entire world."
With this, the Rebbe is clearly implying that he is like the foundation stone. He exists forever and is not subject to any sort of physical change, even if the opposite appears to be true.
The Rebbe said the following:
1) "...until everlasting life of the time to come, souls in bodies without any interruption in the coming of our righteous Moshiach from the tribe of Yehuda and Moshe and Aharon with them and the forefathers with them and the leader of our generation at our head. And I'm the one to start it—to life, to life and to blessing."
The Rebbe tells us that since our generation is the last of exile and the first of Redemption, the concept of the soul leaving the body does not apply to him.
2) "The difference between our generation the ninth [since the Baal Shem Tov]* and the previous one (the eighth) is that previously, due to the fact that Redemption had not yet come...the soul [of the previous Rebbe] was unable to remain in a body in its complete form. (There had to be the concept of the soul leaving the body)... Whereas in our generation, the last generation of exile and the first of Redemption...not only is there nothing missing, but on the contrary, there is a higher completion...Since we live in a way that the soul is in the body, we receive the inner essence of G-dliness. This happens through the immediate arrival of our Righteous Moshiach. 'Please send through the hand (of whom) you will (eventually) send.' And he, Moshiach, will teach everyone the new Torah.'
The Rebbe describes this phenomenon in our generation of uninterrupted life.
3) ..."Souls (that on their part want to cleave [to their source]) in bodies (that want to return [to this world]) specifically and until the everlasting life of the world to come (and concerning our generation) without interruption in the meantime, the life of the body specifically and in a way that the soul is nourished from the body." The Rebbe adds: "And the elevation of returning to dust is (spiritually) through the nullification of "let my soul be as dust to all." The Rebbe explains: "Everything is from dust (Koheles 320), and therefore through nullifying [ourselves], we can become like dust, a vessel for all the good things until the thing that is the best, Torah."
The Gerrer Rebbe in his famous book, Sfas Emes, (c.1900), says the arrival of the descendant of David is separate and the Redemption is separate. Moshe Rabbeinu (Moses) came to Egypt before the Redemption, and so it can be at the future Redemption, as explained in Midrashim. Just as the first redeemer was revealed and then hidden, so, too, the final redeemer. The first redeemer, Moshe, came and informed the Jews about the news of the Redemption, that G-d remembered them and would take them out of Egypt. This means the redeemer came and was revealed, even though he had not yet performed any actions of Redemption, and the conditions of exile were still in its full intensity. In the book of Daniel; (12:12), Rashi comments "there will come a time when our King Moshiach will be concealed after he has been revealed and then he will return and reveal himself [again]." This applies to the present situation in which we find ourselves. The Rebbe is here just as before; however, to our eyes he is concealed and we are awaiting his final revelation.
Since the 3rd of Tammuz (5754-1994), we are no longer able to physically see the Rebbe King Moshiach. The Rebbe remains physically alive just as before; it is only to our eyes that he is concealed. Therefore we call this a day of concealment, and many refer to this as the "last test." Just as we know that there is a G-d though we may not see him, so, too, the Rebbe King Moshiach is here even though we do not see him.
We are facing a great test, but G-d has already taught us in the Torah how to overcome any test: We follow the words and instructions of G-d and His prophets. One of the most famous stories in the Torah relates how Avraham Avinu (our forefather Abraham) was told by Hashem to take his own son Yitzchok and sacrifice him. This is known as Avraham's tenth and final test that was given to see if he would listen to G-d without any doubts or hesitations. On Avraham's way to Mount Moriah, Satan tried many times to convince him not to fulfill G-d's orders, even turning himself into a wide rushing river to block the way so that Avraham would give up. When Avraham reached the river, however, he didn't hesitate, but walked into it. He got wet and tired, but as soon as the water reached his head, the river suddenly vanished. Avraham gave us as an inheritance the strength to overcome any obstacles and devote ourselves completely to whatever G-d tells us.
Three hundred sixty-three years later, Moses dampen the faith of the Jews in G-d and show the world that the Jewish nation was vulnerable. The Torah commands us to erase Amalek, which can also be done spiritually. The numerical value of the word Amalek in Hebrew is equivalent to that of the word Sofek (doubt). Every time we erase our doubts in Hashem, we fulfill this commandment.
This applies to us today. We can vanquish Amalek by believing 100 percent in the Rebbe's words without a doubt. The Rebbe's words are G-d's eternal words, the only reality. By erasing any doubts, we will overcome this last test. The Rebbe told us that our generation is the last generation of exile and the first generation of Redemption.
According to the Arizal, the last generation of exile is a reincarnation of the generation that left Egypt with Moshe Rabbeinu.
As the reincarnation of that generation, we have to correct what was not done the first time by having total faith, belief and devotion in our leader, the Moshe of our generation (Moshe Rabbeinu — he is the first redeemer and the last redeemer,) the Lubavitcher Rebbe, Rabbi Menachem Mendel Schneerson, King Moshiach, who lives forever.
The Rebbe announced that the time of the Redemption has arrived. All that's left for us to do now, he told us, is to greet our righteous King Moshiach in such a way that every commandment we keep and every good deed we do has to be specifically with the purpose of doing it in order to greet Moshiach.