The Alter Rebbe teaches that spiritual sadness and inner struggle should be transformed into vigorous service of God, and that the very resistance encountered by the soul can generate greater strength and joy in divine service.
וְהִנֵּה, עֵצָה הַיְּעוּצָה לְטַהֵר לִבּוֹ מִכָּל עֶצֶב וְנִדְנוּד דְּאָגָה מִמִּילֵּי דְעָלְמָא, וַאֲפִילוּ בָּנֵי חַיֵּי וּמְזוֹנֵי, מוּדַעַת זֹאת לַכֹּל מַאֲמַר רַבּוֹתֵינוּ־זִכְרוֹנָם־לִבְרָכָה: ״כְּשֵׁם שֶׁמְּבָרֵךְ עַל הַטּוֹבָה כוּ׳״, וּפֵירְשׁוּ בַּגְּמָרָא: ״לְקַבּוּלֵי בְּשִׂמְחָה״, כְּמוֹ שִׂמְחַת הַטּוֹבָה הַנִּגְלֵית וְנִרְאֵית, כִּי ״גַּם זוֹ – לְטוֹבָה״, רַק שֶׁאֵינָהּ נִגְלֵית וְנִרְאֵית לְעֵינֵי בָשָׂר, כִּי, הִיא מֵ״עָלְמָא דְאִתְכַּסְיָא״ שֶׁלְּמַעְלָה מֵ״עָלְמָא דְאִתְגַּלְיָיא״, שֶׁהוּא – ו״ה מִשֵּׁם הֲוָיָ״ה בָּרוּךְ־הוּא, וְ״עָלְמָא דְאִתְכַּסְיָא״ – הוּא י״ה, וְזֶהוּ שֶׁכָּתוּב: ״אַשְׁרֵי הַגֶּבֶר אֲשֶׁר תְּיַסְּרֶנּוּ יָּ״הּ וְגוֹ׳״. וְלָכֵן אָמְרוּ רַבּוֹתֵינוּ־זִכְרוֹנָם־לִבְרָכָה, כִּי ״הַשְּׂמֵחִים בְּיִסּוּרִים – עֲלֵיהֶם הַכָּתוּב אוֹמֵר: וְאוֹהֲבָיו כְּצֵאת הַשֶּׁמֶשׁ בִּגְבוּרָתוֹ״, כִּי, הַשִּׂמְחָה הִיא מֵאַהֲבָתוֹ קִרְבַת ה׳ יוֹתֵר מִכָּל חַיֵּי הָעוֹלָם הַזֶּה, כְּדִכְתִיב: ״כִּי טוֹב חַסְדְּךָ מֵחַיִּים וְגוֹ׳״, וְקִרְבַת ה׳ – הִיא בְּיֶתֶר שְׂאֵת וּמַעֲלָה לְאֵין קֵץ בְּ״עָלְמָא דְאִתְכַּסְיָא״, כִּי ״שָׁם חֶבְיוֹן עוּזּוֹ״ וְ״יוֹשֵׁב בְּסֵתֶר עֶלְיוֹן״, וְעַל כֵּן זוֹכֶה לְ״צֵאת הַשֶּׁמֶשׁ בִּגְבוּרָתוֹ״ לֶעָתִיד לָבֹא, שֶׁהִיא יְצִיאַת חַמָּה מִנַרְתֵּקָה, שֶׁהִיא מְכוּסָּה בּוֹ בָּעוֹלָם הַזֶּה, וְלֶעָתִיד – תִּתְגַּלֶּה מִכִּסּוּיָהּ, דְּהַיְינוּ, שֶׁאָז יִתְגַּלֶּה עָלְמָא דְאִתְכַּסְיָא, וְיִזְרַח וְיָאִיר בְּגִילּוּי רַב וְעָצוּם לְכָל הַחוֹסִים בּוֹ בָּעוֹלָם הַזֶּה וּמִסְתּוֹפְפִים בְּצִלּוֹ, צֵל הַחָכְמָה, שֶׁהוּא בְּחִינַת צֵל וְלֹא אוֹרָה וְטוֹבָה נִרְאֵית, וְדַי לַמֵּבִין:
The following is sound counsel as to how to cleanse one’s heart of all sadness and of every trace of worry about mundane matters, even about children, health, and sustenance. Everyone is familiar with the statement of the Rabbis that “Just as one must recite a blessing for the good, [one must also recite a blessing for misfortune].” In the Gemara it is explained that one should accept [misfortune] with joy, like the joy of a visible and obvious benefit, for “this is also for the good,” except that it is not apparent and visible to mortal eyes because it stems from the “hidden world” which is higher than the “revealed world,” the latter emanating from the letters vav and hey of the Name of Havaya, whereas the “hidden world” represents the letters yud and hey. Hence the meaning of the verse, “Fortunate is the man whom You chastise, O L–rd.” Therefore, the rabbis, of blessed memory, commented that it is to those who rejoice in their afflictions that the verse refers: “But they that love Him shall be as the sun going forth in its might.” For this is the joy of desiring the nearness of G–d more than anything in the life of this world, as is written, “For Your kindness is better than life…,” and the nearness of G–d is infinitely stronger and more sublime in the “hidden world,” for “The concealment of His strength is there,” and “The Most High abides in secrecy.” Therefore, [the man who accepts affliction with joy] merits [to see] the “sun going forth in its might”—in the World to Come, i.e., the sun emerging from its sheath in which it is enclosed in this world. But in the World to Come it will appear out of its covering, meaning that then the “hidden world” will be revealed and will shine and send forth light in a great and intense revelation to those who had taken refuge in Him in this world and had taken shelter under His “shadow”—the shadow of wisdom (chochmah), i.e., in the sense of “shade” as differing from light and revealed goodness. Suffice it for him who understands.