Everything is by Divine Providence. If a leaf is turned over by a breeze, it is only because this has been specifically ordained by G-d to serve a particular function within the purpose of creation.
The Baal Shem Tov's revolution was not in the discovery of this universal truth, but in the "depth of heart and fire of soul" that he revealed within this profound mitzvah, which changed the face of Judaism for all time to come.
Many a scholarly mind of his day found the notion absurd. That G‑d cared about the righteous deeds of those who did His will, that they understood. But why on earth would a great G‑d care about a fallen leaf in some forsaken forest?
Rabbi Israel Baal Shem Tov explained the process by which G‑d creates something from nothing. Like many of his teachings, it is revolutionary at the same time that it merely elucidates traditional, age-old teachings.
When the two neighbors would pass each other in the yard, the scholar would throw the crass materialist a look of contempt and hurry on to his holy pursuits.
From the writings of Rabbi Yosef Yitzchak of Lubavitch
Angels don’t say l’chaim on Simchat Torah, so they arose to sing G-d’s praises in the heavens at the usual time. They found heaven littered with strange objects: torn slippers, broken heels. "Yes," admitted the angel Michoel, "this is my merchandise"
"The one," said the Baal Shem Tov, "who knows the answer to the question, 'How can one overcome the pride in one's heart?' -- he is the man who can guide you in your service of the Almighty"
It was an age of boors and ascetics, a time of conflict between body and soul. Then a master appeared. "Don't beat your beast," he taught, "don't overload him and don't abandon him. Help him"