Our L-rd and the L-rd of our fathers, rule over the entire universe in Your glory, be exalted over the entire land in Your splendor, reveal Yourself in the majestic grandeur of Your strength over all who dwell in Your inhabited world. (Rosh HaShanah Amidah)
I. The Festivals and Their Themes
Each of our holidays or festivals has a theme that is fundamental to the Torah. Pesach recalls our redemption from Egypt. The redemption is evidence of Hashem’s omnipotence and through His redemption He established us as His nation. Shavuot recalls Revelation. Our observance of the Torah – its mitzvot and its lessons – is based upon Revelation. Sukkot recalls our travels in the wilderness. It reminds us of our dependence upon Hashem. It dispels the illusion that we have control over our destinies or that our efforts determine our successes or failures. Yom Kippur is devoted to repentance and atonement.
Even Chanukah and Purim emphasize fundamental themes. Rambam – Maimonides – explains that they reinforce the message that Hashem hears our prayers and “the Torah’s assurance that ‘What [other] great nation has a L-rd close to it like Hashem, our L-rd, in all instances that we call-out to Him.’” In other words, when the Jewish people are in danger and we call-out to Hashem for salvation, He responds to our pleas.
II. The Theme of Rosh HaShanah
The theme of Rosh HaShanah is easily overlooked. Rosh HaShanah initiates the Ten Day of Repentance. As Rambam explains, the blasts of the shofar are a signal that the time has arrived to devote ourselves to self-evaluation and repentance. “Awake! Awake, those who sleep, from your sleep. Bestir yourselves, those who slumber, from your slumber. Inspect your actions, repent and recall your Creator.” This emphasis on repentance and the approach of Yom Kippur – the day of which we will be judged – can obscure Rosh HaShanah’s own unique theme.
The theme of Rosh HaShanah is expressed in the above lines. They introduce the final paragraph of the Rosh HaShanah Amidah’s central benediction. Rosh HaShanah celebrates Hashem’s sovereignty. Rav Yosef Dov Soloveitchik Zt”l, quoting his childhood teacher, often described the day as Hashem’s coronation.
Hashem’s sovereignty is a fundamental message of the Torah. But, do we need Rosh HaShanah to remind us of this sovereignty? Every mitzvah we perform, our every prayer and petition attest to His sovereignty. Why is a festival devoted to a theme that is given ample emphasis every day? An answer to this question is provided by an important insight developed by Rav Yosef Dov Soloveitchik in response to a baffling question.
I am Hashem your L-rd who took you out from the Land of Egypt, from the house of bondage. (Sefer Shemot 20:2)
III. The Commandment to Believe in Hashem
Rambam understands the above passage to state a commandment. We are required to affirm the existence of Hashem.
“The first commandment is the commandment that He commanded us in the knowledge of the L-rd. [The commandment] is that it should be known that there exists a cause and He acts upon all that exists.”
Rambam elaborates upon this commandment in his Mishna Torah – his code of law. He explains that we are commanded to know that Hashem is the source of all that exists. The existence of the universe and all contained within it is sustained by the will of Hashem. If He would suspend His will for a moment the universe would immediately cease to exist.
The difficulty with Rambam’s position is blatantly evident in his phrasing of the commandment. “[It] is the commandment the He commanded us in the knowledge of the L-rd.” In other words, Hashem commands us to affirm His existence. This seems completely circular. One’s acceptance of the existence of such a command presupposes that Hashem exists and He issued the command. The command to affirm His existence is meaningless. Our affirmation is expressed in every commandment that we observe.
Furthermore, the very premise of the commandment is incomprehensible. To whom is the commandment directed? Does the commandment admonish the non-believer to believe? First, why would the non-believer accept the legitimacy of a commandment given by a L-rd in whom he does not believe. But if we imagine the non-believer to be moved by the commandment, what is he to do? Is he to try harder to believe? Beliefs are not like actions. Actions are volitional. Beliefs are involuntary. One cannot acquire a belief simply by closing one’s eyes and imagining something is true.
Responding to this question Rav Soloveitchik suggests:
“The first law in the Mishna Torah is the positive mitzvah to know that there exists a first cause [for all that exists]. By “know” the Rambam did not mean to know scientifically or philosophically. “Know” means to experience. The Rambam uses the word the way it’s used sometimes in TaNaCh, in Chumash, “And Adam knew Chavah, his wife” or “And the L-rd knew.” G-d knew? Of course, He knew, but “And the L-rd knew,” the Ramban says it means He had mercy upon them, compassion. Or “And Hashem knew” means Hashem was involved in exile, His Divine presence was in exile. The Sacred One, Blessed be He, figuratively speaking, experienced exile.” 
III. Experiencing Hashem
According to Rav Soloveitchik the commandment is addressed to one who believes in Hashem. This commandment does demand affirmation of Hashem’s existence. It demands that we transform our belief into experience. We must experience His existence.
What does it mean to experience Hashem’s existence? To answer this question, we must consider a phenomenon with which we are all familiar. One can know that something is true and not integrate that knowledge into one’s decisions and life. Let’s consider two examples.
First, consider a person who deeply loves his wife and children. He knows how important these people are to him and the meaning they bring into his life. This knowledge may or may not be integrated into the manner he behaves toward his family. Does he treat his wife with the respect and sensitivity that she deserves? Does he set aside time to spend with his children, take an interest in their daily lives, thoughtfully mentor and counsel them? Some of us struggle to give our love these forms of meaningful, concrete expression. This does not mean that we do not feel love and appreciation. Our failure is in integrating those feelings into our daily behaviors.
Second, a person knows that his cholesterol is high, his blood pressure should be lower. Despite his awareness and his recognition of the danger in which he is placing himself, he is not careful about his diet and does not exercise with regularity. He is not unaware of his peril. He has not succeeded in integrating the knowledge into his life-style.
Both examples illustrate the distinction between knowing a truth and experiencing it or integrating that truth into one’s daily life. According to Rav Soloveitchik, this is the essence of the commandment to “know” Hashem. We are not commanded to affirm His existence. We are commanded to integrate our awareness of Hashem into our daily lives.
IV. Integrating Hashem into our lives
An integrated life is one in which the awareness of Hashem is expressed in all its aspects. The awareness is not limited to the synagogue or to the moments at home when one is engaged in ritual. The awareness informs our interactions with the members of our family, our professional lives, even our personal habits and behaviors.
Rosh HaShanah celebrates Hashem’s sovereignty. It is not intended to make us aware of His sovereignty. It is intended to move us to integrate that awareness into all aspects of our lives. Rosh HaShanah is observed the first two days of the year, but its impact is intended to extend to every and moment of our lives.
 Rabbeinu Moshe ben Maimon (Rambam / Maimonides) Mishna Torah, Introduction.
 Rabbeinu Moshe ben Maimon (Rambam / Maimonides) Mishna Torah, Hilchot Teshuvah 3:4.
 This question does not apply to the other festivals. For example, it is true that we affirm Revelation with the performance of each commandment. However, the affirmation is implicit. In contrast, the performance of mitzvot is not an implicit acknowledgement of Hashem’s authority or sovereignty; it is its explicit expression.
 Rabbeinu Moshe ben Maimon (Rambam / Maimonides) Sefer HaMitzvot, Mitzvat Aseh 1.
 Rabbeinu Moshe ben Maimon (Rambam / Maimonides) Mishna Torah, Hilchot Yesodei HaTorah 1:1-3.
 Rav David Holzer, The Rav Thinking Aloud on the Parsha, Sefer Shemot pp. 149-50. See Rav Holzer’s footnote 291.