[A] principle of faith is a belief or standard without which a particular faith cannot stand. For example, without the belief in the divinity of Torah, there is no Judaism: one who keeps the entire Torah but does not believe it was communicated by G-d may be a disciplined person, but he does not believe in the Jewish faith.
The question, then, of whether a particular belief or standard is to be included among the principles of the Jewish faith is in essence a question of whether Judaism can be described as such without that particular belief.
Is Moshiach a principle of the Jewish faith?
There are classic authorities who maintain that belief in Moshiach is not a principle of our faith. The Chasam Sofer, for example, writes as follows:
“I find it absolutely impossible, however, to believe that our Redemption is one of the fundamentals of our faith—a foundation without which the entire wall would collapse, G-d forbid!
Are we saying that if, G-d forbid, our sins would have caused G-d to expel us [from our land] forever—as R’ Akiva holds with regard to the ten tribes, that they are lost forever—those exiled would be permitted to cast off the yoke of Heaven, or even change a minute detail of a rabbinical law [because they have no hope of redemption]?!
We don’t serve G-d in order to eat from the fruit of the land and to be satiated from its plenty. Rather, “to do Your will, my G-d, is my desire!” Regardless of what He does with us, we remain His servants. This belief [of the Redemption] is neither a principle nor a foundation on which to erect any structure.
Nevertheless, since the foundation of all is to believe in the Torah and the Nevi’im, and these speak of an ultimate Redemption—in parshas Nitzavim and Ha’azinu (as explained there by the Ramban) and in numerous places in Nevi’im—one who denies this Redemption denies the principle of belief in the Torah and Nevi’im.”
In a similar vein, R’ Chisdai Kerashkash succinctly stated about the belief in Moshiach and the Resurrection: “It is a good and proper belief, but it shouldn’t be included as a principle [of faith].”
Notwithstanding the position of these Torah giants, however, the fact remains that the Jewish people have universally accepted the Rambam’s thirteen principles of faith, one of which is the belief in the coming of Moshiach.
Even if it were not considered a principle of faith as such, the belief in the coming of Moshiach has nevertheless kept Judaism’s emotional component intact even in the most difficult of times, giving us hope and vision for a better future.
In Kabbalah and Chassidus we find a wealth of information on the inner meaning of Moshiach and the Redemption—information that helps us appreciate why Moshiach is considered a principle of faith, a tenet upon which stands the entire structure of Judaism. But let us begin…
“In the beginning…”
According to Chazal, Moshiach is alluded to already in the first verses of the Torah, which describe G-d’s creation of the universe:
“In the beginning G-d created the heavens and the earth. …And the spirit of Hashem was hovering over the waters.” Commenting on the latter verse, the Midrash says: “The ‘spirit of G-d’ is the spirit of Moshiach.” At the very inception of the universe, then, the spirit of Moshiach is already present. Rabbeinu Bachaye explains: “This verse tells us the end at the beginning, pointing out that the purpose of creation is to reach the days of Moshiach.” A different maamar Chazal states this explicitly: “Rabbi Yochanan said: ‘The world was created solely for Moshiach.’”
The idea that Moshiach is the purpose of Creation is repeated many times and in numerous sources. The Tanya, for example, says: “It is known that the era of Moshiach, especially when the dead will be resurrected, is the ultimate purpose and perfection of Creation.”
To understand and appreciate why the era of Moshiach is the purpose of Creation, we must have a better understanding of the purpose of Creation.
Why did Hashem create the world?
Chazal tell us that the world was created “for the sake of the Torah and the sake of the Jewish people.” “G-d made a condition with Creation: ‘If the Jewish people accept the Torah, you will continue to exist; if they do not, I will return you to a state of nothingness and emptiness.’” This means, in essence, that Creation came about in order to allow for the performance of Torah and mitzvos, which require the existence of time, space and physical matter. It follows, then, that only when Torah and mitzvos will be observed unhindered will the world have realized its purpose.
When we look closely at the promises of the Torah, the Nevi’im, and the words of Chazal pertaining to Moshiach, we find that they describe the days of Moshiach as one in which the above ideal will be achieved.
Until the arrival of Moshiach, especially in Galus, the fulfillment of mitzvos in a complete manner is not possible. For one, we lack the physical conditions that would facilitate this kind of observance, such as the presence of the Beis HaMikdash and the presence of all Jews in Eretz Yisrael: hundreds of mitzvos hinge on these two conditions alone! Additionally, there are various evil regimes in the world where the practice of Judaism is greatly restricted or even prohibited (though this has improved dramatically over the course of the last two and a half decades). Also preventing the perfect observance of Torah and mitzvos are some dark traits still present in the human psyche—e.g., envy and greed, which lead to rivalry, strife, and so on—as well as physical hardships resulting from things like hunger, sickness, war, the need to earn a livelihood, etc. The latter force us to busy our minds and hearts with mundane and negative matters instead of with the love and fear of G-d.
In the days of Moshiach, however, all of the abovementioned obstacles will be completely removed, and Torah and mitzvos will be observed to the fullest.
An abode in the lower realms
Chassidic teaching gives us deeper insight into the perfection that will be achieved in the era of Moshiach. Citing a Midrash that says, “G-d desired a dwelling place in the lowest realm,” Chassidus explains that G-d desired a world in which His presence would be greatly concealed (hence the term “lowest realm) only to be revealed through the efforts of man. In other words, man would eventually transform the world into a home for G-d; into a place where He would be revealed in His glory and essence.
The tools for this revelation would be Torah and mitzvos:
G-d and the Torah are one
Kabbalah and Chassidus explain that the wisdom and will of G-d, as expressed through Torah and mitzvos, serve as the channels through which G-dliness is drawn into the world. This process of revealing Hashem in the world began with the construction of the Mishkan:
G-d chose as His dwelling place—that is, as His place of revelation—a structure built from physical materials contributed by the Jewish people. Through hard work carried out in accordance with Hashem’s directives, physical objects such as wood and gold and silver became part and parcel of the physical structure that would serve as a dwelling place for Hashem. In this structure, Hashem eventually rested His presence—which the Jewish people gathered three times a year to stand before—“to see and be seen”—and from this structure G-dliness issued forth into the world, allowing for the divine communication known as prophecy. This structure also served as the passageway through which the prayers of all Jews around the world and the prayers and divine service of the kohanim and leviyim ascended On High, to be warmly accepted by G-d.
The ultimate purpose of the Mishkan and Beis Hamikdosh is to enable and energize the performance of Torah and mitzvos so that they eventually bring about G-dly revelation in every part of the world, transforming the entire world into an abode for G-d, a Mishkan/Beis Hamikdosh in macrocosm. With the culmination of this transformation, the purpose of Creation—to make for G-d “a dwelling place in the lowest realm”—will have been achieved.
“All flesh will see”
The time period in which the world will be a dwelling place for Hashem, a home in which He will be fully revealed, is the era of Moshiach. Indeed this is what defines the era Moshiach. At that time, “G-d’s glory will be revealed and all flesh together will see that the mouth of G-d has spoken.” As a result of this great divine revelation, the Gentiles too will accept G-d’s sovereignty and serve him in unison, and “the sole occupation of the world will be to know G-d Alone.”
The G-dly state of the world in the days of Moshiach is described in numerous prophecies and is beautifully depicted in the “Aleinu“ prayer: “We therefore hope to You, O Lord, our G-d, to swiftly see the glory of Your might…to rectify the world with the kingship of the Al-mighty, and all the children of flesh will call in Your Name…all inhabitants of the world will acknowledge and know that to You every knee shall bow…to the glory of Your Name they will offer splendor, and they will all accept upon them the yoke of Your kingship…and You will be king over them speedily for all eternity…on that day G-d will be one and His Name will be one.”
When viewed in light of the above, Moshiach is indeed a foundation of Judaism—arguably the foundation of Judaism. For Moshiach is not merely one who redeems a particular nation from hardship but one who brings about the very fulfillment of Judaism’s purpose—that the world be a dwelling place for G-d.
 There are numerous higher, spiritual realms.