[The sages say:] Yom Kippur atones only for those who repent.
Rabbi [Judah HaNassi] says: Yom Kippur atones whether one repents or one does not repent.
Talmud, Shevuot 13a
On Yom Kippur, the day itself atones... as it is written, For on this day, it shall atone for you.
Mishneh Torah, Laws of Repentance 1:3
Citing the prophet Isaiah's call, "Seek G‑d when He may be found, call upon Him when He is near," the Talmud says: "These are the ten days between Rosh Hashanah and Yom Kippur." These ten days, called The Ten Days of Teshuvah, are the most solemn days of the year -- days designated for soul-searching and return (teshuvah) to G‑d. G‑d is near--more attentive to our prayers, more accepting of our repentance, than on the other days of the year.
But are there ten days between Rosh Hashanah and Yom Kippur? Rosh Hashanah occurs on the first and second days of Tishrei, while Yom Kippur is on the tenth of that month. Thus, the Ten Days of Teshuvah include Rosh Hashanah and Yom Kippur. Indeed, teshuvah is a dominant theme in the observances and prayers of both festivals. Yet the Talmud, in the above-quoted passage and in other places, speaks of the ten days between Rosh Hashanah and Yom Kippur.
Chassidic teaching explains that while Rosh Hashanah and Yom Kippur are themselves days of teshuvah, they each embody a principle that goes beyond the concept of return: the essence of Rosh Hashanah precedes teshuvah, while the essence of Yom Kippur supersedes teshuvah. Thus, the Ten Days of Teshuvah include the days of Rosh Hashanah and Yom Kippur and, at the same time, are the ten days between Rosh Hashanah and Yom Kippur.
The Virtue in Sin
The Torah describes the people of Israel as "the nation close to Him." What does it mean that we are close to G‑d? There are three fundamental aspects to our relationship with the Almighty and the manner in which it is expressed in our lives.
On the most elementary level, we achieve connection with G‑d through our observance of the mitzvot, the Divine commandments. The mitzvot embody the will of G‑d; by observing the mitzvot and making their fulfillment the substance and aim of our lives, our souls and bodies become vehicles of the Divine will.
But when a person violates the Divine will, G‑d forbid, he uncovers an even deeper dimension of his bond with G‑d. The connection created by the mitzvah is exactly that -- a connection created between two separate entities. Taken on its own, this connection does not point to any intrinsic bond between the two. In fact, it implies that the natural state of the doer of the mitzvah is one of separateness and distinction from G‑d -- a state which is overcome by the act of the mitzvah, which bridges the gulf between the mortal and the Divine. But when a person transgresses a Divine command, a deeper bond with G‑d comes to light. His inner equilibrium is disturbed; his soul finds no peace and is driven to compensate for its devastated identity with material excesses or profane spiritual quests. His transgressions highlight the fact that there is nothing more unnatural than a soul estranged from her G‑d.
Teshuvah is a soul's experience of the agony of disconnection from its source and its channeling of this agony to drive its return to G‑d. Thus, our sages have said that the sins of a baal teshuvah (returnee) are "transformed into merits," and that he attains a level of relationship with G‑d on which "even the perfectly righteous cannot stand." His transgressions become virtues, for the distance and disconnection they created have become the impetus for greater closeness and deeper connection. His sins have provoked -- and his teshuvah has actualized -- a dimension of his soul's connection to G‑d which a perfectly righteous life never touches.
The One of the Year
But there is also a third, even deeper, dimension to our bond with G‑d.
The two types of connection discussed above have one thing in common: they both allow for the possibility of disconnection. The mitzvah relates to the level on which our finite and mortal nature set us apart from G‑d -- a state of affairs which the mitzvah comes to overcome. The transgression makes the opposite point (that connection with G‑d is the natural state of every soul) with its very dissevering of this connection, teshuvah being the consequential effort to restore the natural bond.
Ultimately, however, there is a quintessential bond between the soul and G‑d that is immutable. On the deepest level of our being, there can be no disconnection, natural or unnatural.
This underlying oneness with G‑d is the root from which the other two levels of connection stem. Every time we do a mitzvah, we draw from this quintessential unity with G‑d the power to overcome our natural apartness and connect to G‑d through the fulfillment of His will. Every time we sin and experience the agony of disconnection from G‑d, this is but another expression of the fact that, in essence, our soul is one with its Creator. And it is this unity with G‑d that empowers us to restore our relationship with G‑d -- on the level on which our transgressions do affect it -- through the process of teshuvah.
These, however, are only glimmers of a deeper truth, expressions of unity rising to the surface of a life that is perceptively distinct and apart. But one day each year, our quintessential oneness with G‑d shines forth in all its glory. This day is Yom Kippur, which the Torah refers to as "the one of the year."
Yom Kippur is more than a day of teshuvah. Teshuvah, "return", implies that, in the interim, one has been somewhere else; Yom Kippur is a day on which we are empowered to actualize that dimension of our soul whose unity with G‑d has never been disturbed in the first place.
Thus, our sages say that on Yom Kippur, "the day itself atones". There is even an opinion, held by Rabbi Judah HaNassi, that the day itself atones even for those who do not repent their sins. For on this day, we achieve atonement for our sins not only by exploiting them as an impetus for return, but also by uncovering that element of self that is never touched by sin at all.
Foundation and End
During the Ten Days of Teshuvah, G‑d makes Himself more accessible to us -- on all three levels of connection discussed above.
It is a period in which special mitzvot are commanded to us (sounding the shofar on Rosh Hashanah, fasting on Yom Kippur, etc.), opening unique avenues of connection to G‑d via the fulfillment of His will.
It is a period of heightened opportunity for teshuvah -- a time when our souls are more sensitive to the break from G‑d caused by our transgressions and more driven to return.
But the foundation and objective of all connection with G‑d is the quintessential bond which requires no deed to effect it and which no deed can affect. In the Ten Days of Teshuvah, the foundation is laid on Rosh Hashanah and attains its ultimate realization on Yom Kippur.
The defining quality of Rosh Hashanah is that it is the day we crown G‑d as king over us. What does it mean that we accept G‑d as our king? The king-subject metaphor is one of many employed by the Torah to describe our relationship with G‑d, which is also referred to in terms of the relationship between husband and wife, shepherd and flock, master and disciple, among others. The king-subject relationship is unique in that it is not defined by equivocal criteria (love, nurture, intellectual appreciation, etc.), but rather involves the abnegation of the subject's very self to the sovereign. On Rosh Hashanah we relate to G‑d as our king, affirming our bond to Him as the very essence of our identity.
Our acceptance of G‑d as king is the basis for our other levels of connection with G‑d -- mitzvot and teshuvah. The concept of a Divine commandment has meaning only after one has accepted G‑d as the authority over one's life; and a transgression is a transgression (and thus an impetus to teshuvah) only because it violates a Divine command.
Thus, the Ten Days of Teshuvah are defined as the days between Rosh Hashanah and Yom Kippur. They are preceded by Rosh Hashanah, since our submission to the Divine sovereignty is the basis for teshuvah -- including the teshuvah we do on the two days of Rosh Hashanah (which are themselves part of the ten). And they are superseded by Yom Kippur, since Yom Kippur, in addition to itself being a day of teshuvah, is the ultimate realization of the soul's quintessential oneness with G‑d -- a oneness which teshuvah expresses and from which teshuvah draws its power, but which transcends the very concept of "return".