6. The miforshim on Nach explain that when a lion attacks its prey, the shepherds gather and shout at it, יחת לא מקולם, but the lion isn't afraid of their shouts. As a group, the shepherds are certainly stronger than a lion, but the lion isn't afraid of them. It is courageous, and that is its strength.
7. These are the words of Shulchan Aruch, יתברך השם בעבודת עליו המלעיגים אדם בני מפני יתבייש ולא, "Don't feel embarrassed before people who mock you in Hashem's service."
The Tanya (ch.26) writes, "There is a great rule that I must tell you: When two people are wrestling if one of them is lazy and moves about heavily, he will fall, even if he is the stronger one. The same is true with the war against the yetzer hara. You can't win this war with laziness and heaviness, which are the product of sadness and a closed heart – a heart as hard as a stone. You only win the battle with zrizus, which comes from a pure heart that is alert, clear from all worldly worries and sadness." Because it isn't always the one who is stronger that wins a war. Zerizus and courage are major factors in the battle's outcome.
Shulchan Aruch begins בבקר לעמוד כארי יתגבר, "Be mighty like a lion to awaken in the morning." Also, in Pirkei Avos (5:20) it states גבור ...הוי שבשמים אביך רצון לעשות כארי, "Be mighty like a lion to do the will of your Father in heaven."
What is unique about a lion? It isn't its strength. There are animals stronger than a lion. The lion's strength is its courage. The Taz (Orach Chaim 1:1) writes, "By its nature, the lion isn't afraid of any animal, as it states (Yeshaya 31:4) יחת לא מקולם, '[The lion] isn't afraid of their shouts.' So too, a person shouldn’t be afraid of the yetzer hara, although the yetzer hara is stronger than him."
And with courage, zrizus, and joy, you can win the war against the yetzer hara.
