The Rebbe was very clear in Likutei Moharan that Esav corresponded to the sitra achra of Malchus, the evil side of malchus. The malchus of Holiness corresponds to prayer, nun, and the receiver of the wisdom of Chochmah. Esav did not receive any such holiness because he participated in hunting (cruelty to animals), sodomy, was stingy with money for the poor, and lied to his father by putting up a good face. He almost caused Yitzchak to sin by pretending that he was trying to be holy when he was not. Rebbe Nachman taught that regarding good deeds, "even a little is good". Esav pretending to his father that he was that little bit of holiness, that he cared about Hashem, when really he did not. He discarded his good lot as firstborn, scorned the birthright and wisdom, and chose for his lot to be one of selfishness and evil.
In Rebbe Nachman's Torah, he taught that the reason why Yaakov was born grasping Esav's heel was because he simply would not allow Esav to prevent him from saving souls. Even at birth Esav knew that Yaakov could save souls with his holy merit. Esav was still the firstborn, but he did not keep that standing. He lost his footing because of his bad deeds. We learn that at birth, the name of our future spouse is called out. This is not permanent either. We always have the chance to change this. It's in our hands who we're destined to marry, based off of our deeds. We can either merit a better option or fail miserably. Similarly, we always have the option of teshuvah.
How can we merit? By every little good deed we do regardless of how small it is. We can fall with sin similarly. It's said that for every two hairs a man shaves from his face, it's worth five sins. It's best not to be discouraged, even though a possible fall would be more powerful than a possible merit, because when a person even contemplates a good deed, he merits. For sins, it is not considered as if he has done anything until he commits the deed. Discouragement is very dangerous indeed.
May we merit to be like Yaakov not Esav, controlling our desires and not sinning in the following week, without discouragement. Amen!