Teshuvah is essentially in the heart, in the mind. It is related to the faculty of binah, understanding.

There cannot be teshuvah without a consciousness of reality:

understanding what is required. Recognition of one's status.

Introspection. Searing soul-searching. Honest self-evaluation that opens the eyes of the mind and causes a profound sense of embarrassment: How could I have acted so foolishly? How could I have been so blind and dumb in the face of the Al-mighty, the Omnipresent "Who in His goodness renews each day, continuously, the work of Creation?" How could I forsake the Ultimate, the Absolute, for some transient illusion? As the prophet laments: "My people have committed two evils: they have forsaken Me, the Fountain of Living Waters, to hew for themselves cisterns, broken cisterns that hold no water!"

Teshuvah is directly related to bushah - shame, embarrassment.

The Hebrew word teshuvah contains the letters of boshet; transposing the letters of shuvah (return), offers the word busha (shame). For bushah is an indication of teshuva.

Bushah, a sense of shame, flows from an illuminating grasp of reality. It is the proof of true regret over, and of a break with, the past. It is identical with teshuvah. To achieve that level is assurance of forgiveness: He who commits a sin and is ashamed of it, all his sins are forgiven him!

It takes understanding to do teshuvah:

"His heart shall understand, and he will return, and it shall be healed for him." That is why first we pray: "...bestow upon us wisdom, understanding and knowledge," and only then: "bring us back to You in complete teshuvah."

Wisdom, understanding, knowledge, are prerequisites for teshuvah.

It takes knowledge to separate right from wrong. Only the wise know to distinguish between holy and profane, between pure and impure. Thus teshuvah is identical with binah.

The ba'al teshuvah becomes aware that sin is a partition between G‑d and man. Sin disturbs the balance of the universe, sundering its unity. "He who transgresses the precepts of the Torah causes a defect, as it were, above; a defect below; a defect in himself; a defect to all worlds."

The word teshuvah can be read as tashuv-hey - returning, restoring the hey.....for when man sins he causes the letter hey to be removed from the Divine Name.

The Divine Name, the manifestation of G‑dliness, is no longer whole. The hey has been severed, leaving the other three letters to spell hoy, the Biblical exclamation for woe.

(The word teshuvah is divisible into these two components: tashuv - hey. Note that the letter hey represents the physical world: this world was created with the hey, because it is like an exedra (closed on three sides and open on the fourth), and whosoever wishes to go astray may do so (has the choice to let himself fall through the open bottom of the hey).

And why is the `leg' of the hey suspended (leaving an opening at the side, from above)? To indicate that whosoever repents is permitted to re-enter.)

"Woe to them that call evil good, and good evil.... woe to them that they are wise in their own eyes....." In turn, "he who does teshuvah causes the hey to be restored...and the redemption depends on this."

Teshuvah restores the hey, recompletes the Holy Name, re-establishes unity, frees the soul.

"Teshuvah corrects everything - it rectifies above, rectifies below, rectifies the penitent, rectifies the whole universe."

The bushah of teshuvah relates only initially to the past.

It develops further into an awareness of personal insignificance in the presence of Divine Majesty. On this higher level it signifies bitul ha-yesh (total self-negation). It diverts one's sights from concern with self to concern with the Ultimate. Thus it ignites a consuming desire to be restored to and absorbed in the Divine Presence: "My soul thirsts for G‑d, for the living G‑d - when shall I come and be seen in the Presence of G‑d...."

"Oh G‑d, You are my G‑d, I seek You earnestly. My soul thirsts for You, my flesh longs for You, in a dry and wary land without water.... or Your loving-kindness is better than life......"

This longing of the ba'al teshuvah is more intense than that of the tzaddik, the saint who never sinned. Having been removed from G‑dliness, the ba'al teshuvah wants to make up for lost time, for lost opportunities.

The energy and passion once expended on nonsense and improprieties are now directed, in ever-increasing measure, towards good. He reaches out with all strength, and thus prompted, leaps to levels unattainable by the tzaddik.

His former transgressions, now responsible for his efforts and achievements, are thus sublimated. His descent, in effect, generated his ascent. The former sins are thus converted into veritable merits.

The status requiring teshuvah is coupled with grief, heart-breaking remorse. The possibility of teshuvah generates hope, faith, confidence: "The heart being firm and certain in G‑d that He desires to show kindness, and is gracious and compassionate, generously forgiving the instant one pleads for His forgiveness and atonement. Not the faintest vestige of doubt dilutes this absolute conviction." Teshuvah is thus marked by great joy as well.

Joy is not only a motivating force for the act of teshuvah, but also a necessary result of it.

For every step away from sin is a step closer to virtue.

Every move away from the darkness of evil is a move closer to the light of goodness, coming ever closer to G‑d.

This fact must fill the heart with joy, a true and encompassing joy and happiness, even as the lost child rejoices in having found the way home.

Indeed, this deep sense of joy, filling one's whole being, is the very test and proof of sincere teshuvah.