פן יהרסו

We know that Chazal teach us that Hashem went around to all the nations before Kabbolas HaTorah to offer them the Torah. When they asked what's written inside, He told them whatever bad Middah that that nation was the most into. They therefore each refused the Torah.
However, Klal Yisroel answered Na'aseh V'N'ishmah. We are ready to accept the Torah even if it runs contrary to our nature.
The question is, what would have been the Mitzvah which Klal Yisroel would have had a hard time with?
I heard from Reb Pinchas Dovid Bunker of Beitar, that that Mitzvah would have been פן יהרסו.
The Neshama of a Yid naturally yearns for Hashem, and cannot bear not being able to come close to Him. This is why many of us find it so hard not to jump to do Avodos which we are not holdinging by.
This is why many of us feel terrible when we're prevented from carrying out those Avodos, or are unsuccesful in them.
Reb Noson of Breslov teaches that even those Yidden who we think are "Kalteh Yidden" who don't feel anything for Avodas Hashem, are also struggling with פן יהרסו. They think that in order to serve Hashem they need to do who-knows-what. If they would only realize that they can serve Hashem right now in their situation with their present abilities, they would recover their Bren.