The connection between t’shuva and the advent of Moshiach is in the sense that the whole point of Moshiach is to bring about innovation, resulting in an entirely new existence. * Inspiration for t’shuva in the month of Elul.
Translated by Boruch Merkur
The Messianic King plays the unique role of bringing profound and fundamental change to the world, as alluded to in the verse, “and all the descendants of Sheis will be obliterated,” meaning the world [as we have known it, will be “obliterated,” i.e., it will cease to exist as it had up until the Era of Redemption, and it] will undergo a change from its very foundation (the name “Sheis” being etymologically linked with “Even HaSh’siya,” the Foundation Stone upon which the entire world is founded, hosheses). All of Creation will be brand new, a completely new existence, as in the verse, “the new heavens and the new earth.”
There is, of course, such a thing as a new structure built upon an old foundation. But a truly new construction is when the base, the foundation (ha’tashtis) of the entire structure is also new.
To elaborate: Moshiach corresponds to the level of Yechida [the most inner, essential dimension of the soul]. By extension, all aspects of the Messianic Era stem from the [general] aspect of Yechida.
Thus, with regard to Torah, in the Era of Redemption there will be the fulfillment of the testimony, “A new Torah shall be issued forth from Me,” meaning not just that we shall have deeper insight into Torah but something entirely new will be established in Torah, something connected with the aspect of Yechida.
Indeed, this profound innovation in Torah, at the level of Yechida, has an impact on the entirety of the world’s existence. It is said, “He looked into the Torah and created the world.” Thus, when G-d looks into “a new Torah,” the automatic result is “the new heavens and the new earth.”
On this basis we can formulate a lesson in our service of G-d:
Since the accomplishments of Melech HaMoshiach will be truly innovative (both with regard to Torah and as a result of that, also with regard to the existence of the world), it is understood that this applies also to our deeds and service to evoke and hasten the advent of Moshiach. Namely, our approach must be specifically in a manner of fundamental innovation.
It does not suffice to add to yesterday’s service of G-d, exceeding our former spiritual achievements incrementally. Rather, our entire approach to serving G-d must undergo profound innovation, resulting in a new structure, as it were, established upon and emerging from a new foundation, literally new.
With this idea in mind we can shed light on the saying, “Moshiach comes to bring the righteous to do t’shuva,” connecting the service of t’shuva with the coming of Moshiach.
With regard to the impact of t’shuva, it is explained in several places that through t’shuva a person becomes an entirely new being, for which reason there is no basis for exacting punishment, etc., for this is not the same person who sinned but an entirely new individual.
Hence, the connection between t’shuva and the advent of Moshiach is in the sense that the whole point of Moshiach is to bring about innovation, resulting in an entirely new existence.
(From the address of Shabbos Parshas Balak 5744)