1. Chazal, in the gemarah in massechet Shabbat 88a, learn from
    pesukim that the Holy One Blessed Be He made a condition with
    the works of creation, “If Yisrael accept the Torah you will have
    permanence, and if not, you will return to be emptiness and
    void.” – see there for the full detail of this conversation.
  2. The Nefesh Hachaim explains this at length in shaar 4:
    chapter 11. The main point of what he says is that apart from
    the Torah scroll that we have in this world, there is a very holy
    spiritual existence in the higher worlds which is also called
    Torah. This is the root of the Torah that we have here in this
    world [see chapter 2 what is explained about this]. From the
    creation of the world until the time of the giving of the Torah at
    Sinai, the whole existence of this world and all the worlds was
    because of this spiritual existence of Torah in the higher worlds.
    This was the way that Hashem established the order of the
    creation. He made it that all bounty can only reach all the
    worlds through the rays of the Torah.
  3. So from the time of the giving of the Torah there was not
    sufficient light from the Torah existing in the higher worlds to
    keep the world going. It therefore became necessary that the
    Jewish nation learn Torah. Through the Torah study of the
    Jewish people here in this world, the upper lights of the Torah in
    the higher worlds are strengthened. Only with this
    reinforcement could there be enough bounty to suffice the
    period after the giving of the Torah. Through Torah study the
    world was able to continue.
  4. The Nefesh Hachaim writes, “The truth is, without a doubt,
    that if the world were to be, from one end to the other be for
    even one moment, empty from our study and meditation of the
    Torah; all the worlds would be destroyed and become nothing
    and emptiness – Hashem forbid.
  5. Hashem has merited us so far and this vacancy has never
    happened and the worlds have not been destroyed, as there are
    always people busy with Torah. Still, the increase and decrease
    of bounty depends on the measure and the amount of our
    busyness with Torah. If we hold onto the Torah with all our
    might, as we should, we acquire eternal life and extra sanctity
    and blessing and great light in all the worlds, spreading out
    from its source hidden high above all the worlds. It also greatly
    corrects and builds up anything that was previously destroyed.
  6. He brings there from Chazal that Torah scholars are the
    pillars of the world, as the verse says, “If not for my covenant of
    day and night, I would not have established the statutes of
    heaven and earth.” They comment further on the verse, “The
    wisdom of the woman built her home.” that Hashem said, “If a
    person merits to study Torah and wisdom, it is as considered
    before me as though he created the heavens, and as if he
    established the whole world.” They continue, “Hashem said to
    Yisrael, ‘My children, busy yourselves with Torah day and night
    and I will credit you as if you support the whole world’.” See the
    Nefesh Hachaim itself for many more sources in Chazal for
    incredible things about how majorly dependent the world’s
    existence is on the Jewish nation’s learning of Torah.
  7. Every person must take these things to heart and review
    them well, [review of the Nefesh Hachaim shaar 4: chapters 11-
    34 are recommended]. In that way a person will value every
    moment of Torah study, and realize how it is something so
    much more important and productive than any worldly
    business, which appear to be such great things. The Torah is
    therefore descried in the pasuk; “It is more precious than pearls
    and all your acquisitions cannot equal it.”