Question: How is it possible to attain happiness?

Reply: A person attains happiness when he feels that he possesses something [of value], when he has acquired something new. The more significant the acquisition, the greater his happiness will be.

Now when a person contemplates that a created being is inherently limited and G‑d gave us the potential to bond with Him through the observance of the mitzvos, [he should realize that he is being given the opportunity for] the greatest ascent possible. Even the highest attainment that a human being could possibly imagine is still limited and cannot at all be compared to the attainment of a bond with the unlimited Creator. Since this is the greatest possible thing to receive, it serves as the source for the greatest happiness.

Moreover, even if a person once stumbled and acted against G‑d’s commandments, he should contemplate and realize [that he is not irrevocably cut off from G‑d]. Although he transgressed G‑d’s will, G‑d still grants him the potential to repent and thus become more cherished to Him than before the sin.1 Indeed, his sins are considered as merits,2 as if they were mitzvos. Therefore, together with the feelings of bitterness that accompanies repentance, he should feel the ultimate happiness that results from his repentance and his becoming pleasing to G‑d again.

Consequently, a person should feel happiness at all times. If he is carrying out what G‑d asks of him, he should rejoice in the observance of the mitzvah. And if he stumbles — and realizes that he has stumbled and regrets his conduct — he should be happy because he can repent and correct his behavior.

(Excerpted from a transcript of a yechidus, 16 Marcheshvan, 5716)