The Unique Event

The Alter of Kelm, zt”l, explains how important the memory of receiving the Torah at Mount Sinai is for our emunah. “See what Moshe said to the entire nation: 'שאל נא לימים הראשונים השמע עם...מדבר מתוך האש'. If we consider this we will understand that our Torah—which was eventually copied by the nations, as the Rambam writes—was given to all of us in fire.
“Go and investigate if there is another nation who claims to have received their tradition in front of every man, woman, and child. Every Jew heard and saw the voice of Hashem speak from within the fire. Why didn’t any other nation make this compelling claim? The simple answer is that they could not. The only thing that would sound plausible is if a so-called prophet claims to have received a vision, possibly with a few disciples as witnesses. This is certainly impossible to verify, unlike our claim that everyone was there, which can easily be checked. Surely it is impossible to convince anyone of this claim if there is not huge evidence corroborating it. If people did not find evidence for such an outrageous claim everyone would emphatically deny it.
“This claim is enough to build one’s emunah. If we will contemplate its truth each day, our emunah will grow strong. But we must never think that dry knowledge of this fact is enough. Instead we must see this in our mind’s eye each and every day. We must understand that the more we do so, the more this is internalized. This is why we are warned, 'השמר לך פן תשכח...יום אשר עמדת'—‘Guard yourselves lest you forget the day that you stood before Hashem your G-d at Chorev.’”