Happiness in Judaism

[9][10] However, in both Maimonides's main legal work and the Code of Jewish Law by Rabbi Yosef Karo, the decrease in joy during Av is mentioned while the increase during Adar is omitted.

[11][12] And though happiness during Adar isn't mentioned in the main Codes, it is mentioned by the Magen Avraham, one of the main commentaries published alongside Karo's work written by Rabbi Avraham Gombiner, and in Kitzur Shulchan Aruch (the "Abbreviated Code of Jewish Law") by Rabbi Shlomo Ganzfried.

[27] The Kabbalist Rabbi Elazar ben Moshe Azikri stated “Though a person may be depressed on account of his sins, he must be joyful at the time of Divine service.

In the early stages of the Hasidic movement, before the name "Hasidim" was coined, one of the names used to refer to the followers of the new movement was di freilicha (Yiddish: די פרייליכע), “the happy ones.”[30] The founder of Hasidism, Rabbi Yisroel Baal Shem Tov (1698–1760) is quoted as saying "In the eyes of the Hasidim, joy is considered a biblical commandment, a mitzvah.

[27][32] And Rabbi Aharon of Karlin (I), one of the early Hasidic masters, reportedly said, "There is no mitzvah to be joyous, but joy can bring on the greatest mitzvot."

[33] In the teachings of Rabbi Schneur Zalman of Liadi, the founder of Chabad Hasidism, happiness is believed to be an essential element in the struggle between the Godly and Animal souls.

[34] Just as it is with a victory over a physical opponent--for instance, two people who wrestle with each other, each striving to fell the other, if one of them is lazy and sluggish he will easily be defeated and will fall, even if he be stronger than the other--so it is with the conquest of one's evil nature: it is impossible to conquer the evil nature with laziness and sluggishness, which stem from sadness and a stone-like dullness of the heart, but rather with alacrity, which derives from joy and an open heart that is unblemished by any trace of worry and sadness in the world.The third Chabad Rebbe, Rabbi Menachem Mendel Schneersohn of Lubavitch taught that a person should be happy and remain in good spirits despite any lack in Yirat Shamayim ("fear of heaven").

[29]: 1:326 According to Rabbi Yisroel Salanter, founder of the Mussar movement, a person may be able to conquer and rectify one's negative impulses by being joyful in his or her service to God.

"[41][42] According to Rabbi Schneur Zalman of Liadi, the first Chabad Rebbe, one may attain joy by thinking deeply and picturing in one's mind the subject of the unity of God.

According to Rabbi Nachman, even a faked, ungenuine, happiness has the power to transform one's personal situation and lead him or her to experiencing genuine joy.

[49] The material in the lessons is drawn from Jewish sources as well as positive psychology addressing the concept of happiness, methods of its attainment as well as possible barriers to experiencing joy.

The lessons also examine how stress over everyday worries can hinder feelings of happiness, and finding purpose and meaning in life are believed to make people happier.