Awakening Innate Love
במדרש ואהבת מי לי בשמים כו' כי הפילוסופים מקשים איך שייך ציווי על אהבה
The Midrash on the verse "You shall love" asks, "Whom do I have in heaven?" (Tehillim 73:25) — for the philosophers raise the difficulty: how can there be a command to love, since love is a matter of the heart and not something that can be obligated?
The Sfas Emes opens with the philosophers' question on the mitzvah to love Hashem: how can love, an emotion of the heart, be made the subject of a command?
אבל האמת יש לבנ"י בשורשם התקשרות ודביקות באל אחד
But the truth is that Bnei Yisrael possess, in their very root, a bond and a dveikus with the One God.
His answer is that the bond and dveikus with Hashem is already planted in the deepest root of every one of Bnei Yisrael, so the mitzvah is not creating something foreign but drawing out what is already there.
וז"ש מ"ל בשמים הוא השורש רק שלמטה יש רצונות אחרים וע"י הקבלה בכל יום עומ"ש ועמך לא חפצתי בארץ
This is the meaning of "Whom do I have in heaven?" — that bond is the root, only that here below a person has other desires; and through accepting the yoke of Heaven anew each and every day by reciting Krias Shema, one comes to the level of "And besides You I desire nothing on earth" (Tehillim 73:25).
On the level of the root, in "heaven," the bond is whole; the trouble is only "on earth," where competing desires arise, and the daily acceptance of ol malchus Shamayim through Krias Shema brings a person to want nothing other than Hashem.
עי"ז יכולין לעורר את האהבה בעוה"ז ג"כ
Through this a person is able to awaken that love in this world as well.
By renewing that acceptance each day, one reaches down and awakens the latent love even within this lowly world.
וכמ"ש ברש"י ומהו אהבה והיו הדברים כו' ע"י התורה
And as Rashi explains, "What is this love? 'And these words shall be...' (Devarim 6:6)" — meaning that the love is awakened through the Torah.
Rashi teaches that the love spoken of is awakened specifically through the words of Torah, "And these words shall be upon your heart."
וג"כ ע"י דברי ק"ש בכל יום כל ימי חיי האדם זוכה אח"כ לבוא לאהבת ה' כמ"ש במ"א:
And likewise, through the words of Krias Shema recited every single day, all the days of a person's life, he afterward merits to arrive at the love of Hashem, as is explained elsewhere.
So too, the steady daily recital of Krias Shema, kept up throughout a person's lifetime, eventually brings him to genuine ahavas Hashem.
Summary: The Sfas Emes addresses the philosophers' challenge to the mitzvah of loving Hashem: how can love be commanded if it is a feeling of the heart? He answers that Bnei Yisrael carry in their very root a bond and dveikus with the One God, so the love is not something foreign that must be manufactured but a hidden treasure that must be drawn out. At the level of the root, in "heaven," this bond is whole and undivided; only here below do competing desires obscure it. Through accepting the yoke of Heaven afresh each day in Krias Shema, and through the words of Torah, a person awakens that latent love in this world, until over the course of a lifetime he merits to arrive at true ahavas Hashem.