It is possible to say that the potential to carry out such Divine service is granted from Above (primarily) on the holiday of Sukkos. Due to the Jews’ observance of the mitzvah of the four species,וְיֵשׁ לוֹמַר, דְּהַנְּתִינַת כֹּחַ מִלְמַעְלָה עַל עֲבוֹדָה זוֹ הִיא (בְּעִקָּר) בְּחַג הַסֻּכּוֹת.
on the holiday of Sukkos, everyone (even non-Jews) know that the Jews prevailed in the judgment of Rosh HaShanah, as stated above.1דְּעַל יְדֵי שֶׁבְּחַג הַסֻּכּוֹת יוֹדְעִים כֻּלָּם (גַּם הַגּוֹיִם כו') שֶׁיִּשְׂרָאֵל אִינוּן נִצּוּחַיָּא,
Moreover, not only are the non-Jews aware of this; they also concur with this judgment,וְנוֹסָף שֶׁהֵם יוֹדְעִים מִזֶּה הֵם מַסְכִּימִים לָזֶה
to the extent that they praise G‑d because “His kindness has overwhelmed us” – i.e., the Jewish people – (as explained above in sec. 3).וְעַד שֶׁהֵם מְהַלְּלִים כו' אֶת הֲוָיָ׳ עַל זֶה שֶׁגָּבַר עָלֵינוּ חַסְדּוֹ (כַּנִּזְכָּר לְעֵיל סְעִיף ג),
This generates the potential for a Jew to carry out his Divine service in a manner that leads to “You will be blessed by all the nations” throughout the entire year.הִנֵּה מִזֶּה נִמְשֶׁכֶת נְתִינַת כֹּחַ עַל הָעֲבוֹדָה דְּבָרוּךְ תִּהְיֶ' מִכָּל הָעַמִּים בְּמֶשֶׁךְ כָּל הַשָּׁנָה.
A further point:וְיֵשׁ לְהוֹסִיף,
The concept of victory (“the Jews prevail”), to refer to the words of the Midrash cited above, implies victory over an adversary.דְּעִנְיַן נִצָּחוֹן (יִשְׂרָאֵל אִינוּן נִצּוּחַיָּא) הוּא שֶׁמְּנַצְּחִים אֶת הַמְּנַגֵּד.
From this, it can be understood that the revelation on the festival of Sukkos that the Jews prevailed in the judgment of Rosh HaShanah which motivates even non-Jews to praise G‑d also includesדְּמִזֶּה מוּבָן, דְּזֶה שֶׁגִּלּוּי הַנִּצָּחוֹן בְּחַג הַסֻּכּוֹת הוּא בְּאוֹפֶן שֶׁגַּם הַגּוֹיִם כו' מְהַלְּלִים כו', הוּא,
those who originally were adversaries.שֶׁגַּם אֵלֶּה שֶׁהָיוּ תְּחִלָּה מְנַגְדִּים,
They too are transformed into friends and alliesגַּם הֵם נֶהְפָּכִים לְאוֹהֲבִים,
and praise G‑d because “His kindness has overwhelmed us.”וּמְהַלְּלִים כו' אֶת הֲוָיָ׳ עַל זֶה שֶׁגָּבַר עָלֵינוּ חַסְדּוֹ.
Therefore, the potential granted on Sukkos for performing Divine service in a manner that calls forth “You will be blessed by all the nations” throughout the entire yearוְלָכֵן, גַּם הַנְּתִינַת כֹּחַ שֶׁנִּמְשֶׁכֶת מֵחַג הַסֻּכּוֹת עַל הָעֲבוֹדָה דְּבָרוּךְ תִּהְיֶ' מִכָּל הָעַמִּים בְּמֶשֶׁךְ כָּל הַשָּׁנָה
includes also those that were previously adversaries.הִיא גַּם בְּנוֹגֵעַ לְאֵלֶּה שֶׁהָיוּ מְנַגְדִּים,
This is also evident from the wording of the verse “You will be blessed by all the nations,” for the term כל, “all,” is all-inclusive, encompassing even those who were previously enemies and opponents; they, too, bless the Jewish people.בָּרוּךְ תִּהְיֶ' מִכָּל הָעַמִּים.
This serves as instruction for every Jew, teaching,וּמִזֶּה הוֹרָאָה לְכָל אֶחָד וְאַחַת מִיִּשְׂרָאֵל,
that even if at times there be people or circumstances that prevent and hinder him from properly carrying out his Divine service,שֶׁגַּם כְּשֶׁיֶּשְׁנָם לִפְעָמִים כָּאֵלֶּה שֶׁמּוֹנְעִים וּמְעַכְּבִים אוֹתוֹ מֵעֲבוֹדָתוֹ,
this should not, G‑d forbid, bring about any weakness in his Divine service.אֵין זֶה צָרִיךְ לִגְרוֹם חֲלִישׁוּת חַס וְשָׁלוֹם בַּעֲבוֹדָתוֹ
(How much more so, is there no room for thoughts of despair, Heaven forbid.)(וּמִכָּל שֶׁכֵּן שֶׁאֵין מָקוֹם לְמַחְשֶׁבֶת יֵאוּשׁ חַס וְשָׁלוֹם),
When he decides to carry out his Divine mission without giving thought to any obstacles or hindrances,וּכְשֶׁמַּחְלִיט לְמַלֹּאות אֶת שְׁלִיחוּתוֹ מִבְּלִי לְהִתְחַשֵּׁב עִם שׁוּם מְנִיעוֹת וְעִכּוּבִים,
he will see clearly, even with his fleshy eyes, that all the obstacles are in fact insubstantial.2אֲזַי יִרְאֶה בְּגִלּוּי בְּעֵינֵי בָשָׂר שֶׁכָּל הַמְּנִיעוֹת אֵין בָּהֶם מַמָּשׁ,
On the contrary, the Divine intent in having presented him with obstacles is to elevate him to a higher plane,וְאַדְּרַבָּא, הַכַּוָּנָה בָּזֶה שֶׁיֵּשׁ לוֹ מְנִיעוֹת הוּא בִּכְדֵי לְהַגְבִּיהַּ אוֹתוֹ לְמַדְרֵגָה נַעֲלֵית יוֹתֵר,
that as a result of overcoming these obstacles he will possess not only the virtues that result from the service of refining the sparks of G‑dliness embedded in material existence, but also those resulting from the service of confronting and overcoming challenges.שֶׁתִּהְיֶ' לּוֹ הָעֲבוֹדָה דְּבֵרוּרִים וְגַם הָעֲבוֹדָה דְּנִסְיוֹנוֹת
(Were it not for such obstacles having presented themselves, he would not reach this level of service,(שֶׁלּוּלֵי הַמְּנִיעוֹת לֹא הָיָ' מַגִּיעַ לַעֲבוֹדָה זוֹ,
for we request – and are commanded to request –שֶׁהֲרֵי מְבַקְּשִׁים וְנִצְטַוִּינוּ לְבַקֵּשׁ
“Do not bring us close… to a challenge.”3)אַל תְּבִיאֵנוּ לִידֵי נִסָּיוֹן),
Since a person obviously does not seek to be confronted with challenges, it is clear that the challenge was presented to him from Above, so that
through it, he will be elevated to a higher level.4 Through the person persevering in his Divine service and proceeding forward despite the challenges,שֶׁעַל יְדֵי זֶה יַגִּיעַ לְמַדְרֵגָה נַעֲלֵית יוֹתֵר,
ultimately, even those who presented these obstacles will be transformed into supporters who confer blessings upon us, as reflected in the verseוְעַד שֶׁסּוֹף סוֹף, גַּם אֵלּוּ שֶׁמָּנְעוּ וְכו' יֵהָפְכוּ לִמְסַיְּעִים וּמְבָרְכִים,
“You will be blessed by all the nations.”בָּרוּךְ תִּהְיֶ' מִכָּל הָעַמִּים,
Through this, G‑d’s intent and desire for a dwelling in the lower realms will be consummatedוְעַל יְדֵי זֶה תֻּשְׁלַם הַכַּוָּנָה דְּנִתְאַוָּה הקב"ה לִהְיוֹת לוֹ יִתְבָּרֵךְ דִּירָה בַּתַּחְתּוֹנִים,
in this material world, the lowest of all realms.בַּתַּחְתּוֹן שֶׁאֵין תַּחְתּוֹן לְמַטָּה מִמֶּנּוּ.

Summary

The potential to carry out Divine service in a manner that calls forth “You will be blessed by all the nations” is granted from Above primarily on the holiday of Sukkos. As evident from the Midrash that describes the four species as symbols of victory, this includes also nations who were opponents, for victory is relevant only in the face of opposition. Even those nations that previously opposed the Jews will be transformed into allies and be motivated to praise G‑d.
This is also alluded to in the verse, “You will be blessed by all the nations.” The word “all” encompasses even those nations who previously presented obstacles to the Jews’ Divine service.
Every person should derive a personal lesson from this motif, realizing that all the obstacles that he confronts in his Divine service are in fact springboards intended to elevate him to a higher rung.