In this week's section, called Yitro (named after Moses' father-in-law), we read about one of the most important events in the history of the Jewish people: the Giving of the Torah. In fact, several of the essential foundations of Judaism are based on this event, such as faith in Moses' prophecy (since we heard God speaking to him) and faith in revelation—that is, that Judaism is not based on an "enlightened" individual, but on a Divine revelation to the entire Jewish people, men, women, and children.
Furthermore, in the Giving of the Torah the Children of Israel become the Jewish people, that is, it is the moment in which God's choice of the Children of Israel (referring to Jacob the patriarch, called Israel) as His people, the Chosen People, is definitively revealed and made effective.
As an introduction to such a historic event, the Torah relates that "God descended upon Mount Sinai" (Shmot 19:20), revealing Himself within a blazing fire and a smoking Mount Sinai (see Shmot 19:16-18).
We know that every story in the Torah contains a lesson about our service to God. (It should be clarified that the idea of service to God does not refer only to what man does for God, such as mitzvot, but also to personal development and refinement, as growth in order to improve one's actions toward God. This, too, is part of service to God.)
Hasidic philosophy explains, from various perspectives and at different levels of depth, the relationship between a giver and a receiver who exist on vastly different planes of existence. One aspect of this relationship involves the giver "descending" to the receiver's level in order to deliver their message. Both the message and the medium through which it is transmitted, as well as the giver themselves, are diminished and condensed to communicate effectively and clearly to a receiver who, as mentioned, is on an infinitely lower plane.
This is what happened at Mount Sinai. God, the Perfect Giver, and we, the Absolute Receivers, exist on infinitely different levels. To establish a connection and deliver a message, "God descended upon Mount Sinai.".
It's like an adult parent getting down on the floor to play with their young child. The environment in which the game is played, and the game itself, occur at the child's level. Furthermore, the parent lowers themselves (physically and mentally) to share the game with their child.
The Torah is the word of God clothed in worldly and material matters, so that we can absorb and internalize the Divine message. Through it, we can reach God Himself, even though it speaks of the journeys of Abraham and the Jewish people through the desert. And anyone who says otherwise: Would anyone argue that an adult rolling in the sand with his two-year-old son is still an adult? Would anyone doubt that someone playing a children's game is truly an adult, and that in that very game, the child finds and connects with the adult, his father?
The Torah was given to be studied so that, through it, we may reach God.