Principle 1: Fixing the foundations of ourselves & of the world
The struggle with lust is a struggle with the deepest human emotions. And therefore, fixing these emotions fixes a person deeper than anything else. That's why the Zohar calls this Yesod. Hashem is not just telling us not to be dirty. Rather, he is telling us to build ourselves with the things we don’t do. The foundation of a building is underground and no one sees it, but it holds up the entire building. Shemiras Habris is the hidden part of a Jew, it's the real you. And if the foundation of a Jew is weak, his whole spiritual structure is fragile and in grave danger of collapse.
It is brought down from the Baal Shem Tov that if a person succeeds in subjugating this particular desire then he is automatically able to subjugate all other desires, as the Mekor Mayim Chaim writes (Baal Shem Tov, Lech Lecha), “For it is from the strength of this desire that man is created, and a person has 365 sinews--parallel to the 365 negative commandments, and by subjugating this he therefore nullifies [the desires for] all 365 negative commandments”. The B’nei Yissachar also writes (Derech Pikudecha): “We have a tradition from our fathers that the Yetzer Hara desires more than anything to attack the person through these sins, because included in this lust are all the others.” Perhaps this is why R’ Nachman also writes that these temptations are a man’s main test in life.
It says in the Korbonos: “Zeh Ha’isheh asher Takrivu LaHashem – This is the fire that you should sacrifice to Hashem.” Isheh means fire, but it also spells Ishah, which means “a woman.” The biggest sacrifice that a man needs to make in his life for Hashem is zeh Ha’isheh – this desire for women and the fire of lust.
By working on these areas, we ultimately learn to give over our entire heart to Hashem, as the Pasuk says “Bechol Levavcha – with all your heart.” And Chazal say “Bishnei Yitzrecha – with both your inclinations.”
And not only are we fixing ourselves deeply through this struggle, we are also fixing the world. Every generation has its tests, and this is likely the test of our generation. There has never been a time in history where promiscuity and licentiousness filled the world in every corner, to the degree that it does in our time. In the generation before Moshiach’s time, we are cleaning out the filth from the very bottom of the barrel. We are doing the final work before the great days that are to come.
Only great souls with immense potential were given this difficult job. So if Hashem gave us this struggle, it means he trusted us with a great mission. This alone should bring us joy and motivation to substantiate His trust. And of course, if we succeed, we will be in the front lines to greet Moshiach!