R’ Yehudah [52a middle]: In the future, when Hashem slaughters the Yetzer Hara (Y”H = evil inclination), there will be crying. The righteous will cry because they will see the Y”H as a huge mountain and recall the pain it took to conquer that great mountain of temptation. The wicked will cry because to them, the Y”H is like a strand of a hair, and they are saddened to have not overcome such a small obstacle. Hashem also “cries” for the righteous (with tears of joy) and the wicked (tears of sadness).
R’ Assi: The Y”H for the wicked is a spider thread; It can be easily swept aside. Once one becomes close to it (and chooses not to distance oneself), the Y”H becomes like a cart rope and they end up entangled in a massive web.
Rif and Chasam Sofer: The Y”H always starts small. But when defeated by the righteous, it grows bigger and stronger with each successive failure to create a more formidable opponent.
T’s Lesson: Evil has been in existence since creation (the snake). We should gain strength from the righteous and try to overcome the battle with it. We should merit to see the evil slaughtered in front of our eyes, whether mountains or hairs.
How often are we tempted by food that is terrible for us? A nutella sandwich is truly terrible for me, but “I can’t help it.” I NEED it. Right?
Using the Gemarah, we would know that this Y”H is just a tiny insignificant hair that can easily be overcome with the simplest ease (Unless we think we are such righteous people! But then we have even bigger problems…). Hashem gives us free will with the power to pass any test we are given. Beat the Y”H now, when it IS easier, before he gets stronger and harder to fight against.
Although it may seem daunting, we know that “kol haschalos kashah” (all beginnings are hard). Once once we get the ball rolling however, momentum and motivation can carry us through to persevere and accomplish our tasks.