Rav Yeruchom: When Accepting The Torah Became a Matter of Life of Death
The gemara (Shabbos 87a) tells us, "SheKafa Aleihem Hakadosh Baruch Hu Es HaHar K'Gigis". At Har Sinai Hashem held the mountain over Bnei Yisroel and told us that if we accept the Torah all will be well, but if we don't then we will die. Why was this necessary given that a few days earlier we all jubilantly proclaimed in unison Naaseh V'nishma?
Rav Yeruchom Levovitz (Maamarim Mishpatim) explains as follows. We know that there are levels of creation; inadamate objects, things that grow, living creatures, and humans who speak. Each one is a step above the one below. What happens when the creation fails to live up to its level? If a flower stops growing it does not become inadamate, rather it dies and disintegrates. The same goes for an animal that is no longer alive. It doesn't continue to grow, nor does it remain in its same state, it decomposes.
Klal Yisroel is in a class apart from the rest of humanity, as we are a creation called "Yisroel". Yisroel is defined as Hashem's people, the people who live by the Torah. The ramification of this is that as soon as we stop living by the Torah we don't lose our status as Yisroel and become just another human being. That is not the way it works. Rather we slowly disintegrate into a nothing.
After Bnei Yisroel joyfully accepted the Torah, Hashem taught us this crucial lesson. As Torah Jews we must live by the Torah for without it we lose our entire purpose and being. We don't have an option to give up our uniqueness and live like the rest of humanity. Relinquishing our status of Yisroel is tantamount to forfeiting existence itself.