Why You Matter

English letter dated 12 Cheshvan, 5722.
See also the English letter dated 24 Nissan, 5723: “It is also clear that success and attainment, whatever the goal in life, depends on inner peace and harmony. A thinking person will have peace of mind only if he has the feeling that his life is worthy and purposeful, and only then will he be able to forge ahead, unmoved by external distractions and unhindered by his own temporary moods or setbacks.”
Similarly, see the English letter dated 10 Tammuz, 5739, responding to a Jewish man who felt his life was meaningless: “The purpose of life on this earth is to make it a fitting abode for the divine presence, which requires that it should be a world where justice, decency, and benevolence reign supreme. And everyone is expected to work for the realization of these ideals to the maximum degree—first and foremost in one’s personal life, and through influencing the environment in this direction. For a Jew, the purpose of life is clearly spelled out in the Torah and is realized through everyday life and conduct in accordance with the Shulchan Aruch. And such a life is meaningful, worthy, good, secure and harmonious.”

Zohar, Vol. I, p. 4a. Tanya, chapter 36.
The Rebbe would often point to the words in Genesis (2:3): “And G‑d blessed the seventh day and He hallowed it, for thereon He abstained from all His work that G‑d created to do.’’ The final words, ”that G‑d created to do,” seem out of place. What does it mean that G‑d created the world “to do”? Rashi, elucidating the commentary of Bereishit Rabbah (11:6), explains that “to do” means “to repair.” The following letter (Igrot Kodesh, Vol. 13, p. 240) explains:
“At the summation of the world’s creation, the Torah says, as explained by our Sages, that ‘G‑d created it to do—to repair.’ This means that the world was created in a way that man should contribute of his own accord not only improvements but also corrections. So long as there exists even one person in the universe, that is in itself evidence that the world still needs repair. And repairing the outside world goes in tandem with repairing one’s internal world…” See also, for example, Torat Menachem 5716, Vol. 1, p. 189 (chabad.org/2987683); Torat Menachem 5744, p. 452; Torat Menachem 5746, p. 411; Torat Menachem 5749, p. 33 (chabad.org/4543686).
Another concept the Rebbe would often reference, found in Tanya, ch. 33, is that our task is to transform the world from a reshut harabim into a reshut hayachid, from a domain of multitude and separation into a domain for the singular divine unity. See, for example, Torat Menachem 5712, Vol. 2, p. 62 (chabad.org/4280217); Torat Menachem 5719, Vol., 1 p. 94 (chabad.org/2987768).

Eitz Chaim 26:1; Tanya, ch. 37.
Drawing on these sources, the Rebbe would often speak of the divine mission every individual has to “illuminate their body, their animalistic soul, and their part of the world” with the light of the divine soul—“The soul of man is the candle of G‑d” (Proverbs 20:26)—and the light of Torah and mitzvot—“The mitzvah is a lamp and Torah is light” (Proverbs 6:23). See, for example, Torat Menachem 5713, Vol. 1, p. 245 (chabad.org/2987869). Torat Menachem 5717, Vol. 1, p. 25 (chabad.org/2988252); Torat Menachem 5725, p. 109 (chabad.org/4313283).

See, for example, Hayom Yom, entry for 3 Elul: “A person who believes in Divine Providence knows that ‘the steps of a man are directed by G‑d’ (Psalms 37:23). [A person goes to] a particular place because his soul must refine and perfect something there.”
See also Hayom Yom, entry for 18 Elul, for a similar teaching of the Baal Shem Tov on the verse “And you shall go to the place that the L-rd your G‑d chooses to make His Name dwell there” (Deuteronomy 26:2).
The Rebbe also pointed to the words Joseph used to comfort his brothers when they unexpectedly met him in Egypt after selling him into slavery years earlier: “Be not grieved, nor angry with yourselves, that you sold me here, for G‑d did send me before you to preserve life.… And G‑d sent me before you to preserve you a remnant in the earth, and to save your lives by a great deliverance. So now it was not you that sent me here, but G‑d….” (Genesis 45:5-8). This, the Rebbe said, as everything in Torah, teaches an eternally relevant lesson: even when we find ourselves in places or situations that seem profoundly negative and dark, there is a divine mission for us to fulfill there. See Torat Menachem 5747, Vol. 2, pp. 170-172.

This analogy is given in Likkutei Sichot, Vol. 30, p. 150. For other iterations of this analogy, see Torat Menachem 5744, Vol. 4, p. 2646; Torat Menachem 5745, Vol. 4, p. 2088.
Alongside the logical reasoning that G‑d’s actions are always intentional, the Rebbe would also point to the Talmud’s teaching (Shabbat 77b): “Rav Yehuda said that Rav said: [Of] everything that the Holy One, Blessed be He, created in His world, He did not create [even] one thing for naught.”
This perspective lends new meaning to the time and talents given to us by G‑d. They are gifts meant to be purposefully used—never wasted. As this handwritten response counsels a young woman (Petakim, Vol. 1, p. 192):
“Since ‘G‑d didn’t create [even] one thing for naught’ [Shabbat 77b], and you were given a talent for mentoring and educating, you should utilize the summer for putting this talent to use. This would mean going to camp…. This way your talent will be activated for the entire summer, for the benefit of the public—and no doubt it will be to your benefit as well—both physically and spiritually.”
Similarly, a 1952 letter (Igrot Kodesh, Vol. 6, p. 252) responding to someone who wrote of his criticisms of the way other people were doing their job (the details are unclear), reads as follows:
“[The verse says,] ‘Days were formed, and there is not one amongst them’ [Psalms 139:16]. Chasidut interprets this [see Torat Chaim, Shemot, p. 600] to mean that a person’s days are measured so that they can fulfill their mission in this world [‘days were formed’], and there isn’t even one day or moment that is extra and unnecessary for the mission [‘there is not one [superfluous] amongst them’]. It is therefore understood that any amount of time—be it even very little—spent on insignificant matters detracts from the fulfillment of the mission.
“Based on the above, it’s a pity on the time you are spending questioning others—asking why they are doing it this way and not that way. That’s a matter for them. What is most proper and necessary for every individual, with the exception of those with communal responsibilities, is to devote their time, energy, and talents to fulfilling their personal mission.”
Similarly reads an English letter from 1970: “Our Sages tell us that G‑d has not created anything in His world for no purpose. They also tell us that every person has been allotted a certain number of days and years. This means that every Jew, as well as every person in general, has been given certain capacities, as well as a certain allotted period of time, in order to fulfill his particular task or mission in the world. There is no excess of capacity, or time, because that would contradict the statement above. At the same time there is no deficiency, G‑d-forbid, in capacity and time, since it would be quite illogical to impose a certain task without providing the means necessary to fulfill it….”

Young Scholar’s Daily Calendar & Encyclopedia (Merkos L’inyonei Chinuch, 1943).