How The Avot Helped Return the World to the Perfection of Adam HaRishon Before the Sin
If we study the essence and lives of the three avot, it can be suggested that they brought the world to a state of Adam HaRishon before the Sin. Breaking down Adam’s sin, we find three elements: one a lack of heeding G-d’s command, second, a fall from kedusha and third, a new existential battle between good and bad. When we look to the avot, we find a tikkun of these three elements. Avraham, unlike Adam, did heed G-d’s commandments, such as lech lecha and to take his son to the akeida. Yitzchak was the tikkun of the lack of kedusha that entered the world after the sin, for Yitzchak had the status of a holy korban; his ashes lying before G-d. Yaakov, emanating from the pure kedusha of Yitzchak, becomes the paradigm of the one who can conquer the evil Eisav who was produced from the tumah of the snake.
The Midrash notes that Avraham came to recognize G-d on his own. He sensed the Almighty and believed in Him. Nonetheless, as Tosefos in Kiddushin points out, to follow commands that you’re obligated in is much more difficult than engaging in voluntary ones; since there is more at stake. This explains the greatness of Avraham. He not only followed G-d’s commands but raised himself up to pass nisyonot that seemed beyond human reach. But the bottom line is Avraham did follow G-d’s commands. He heard, listened, and did. This is in stark contrast to Adam, who took the advice of Chava, and did not heed G-d’s command to refrain from eating from the tree. Adam had one central command upon him, and he couldn’t hold it. Avraham had numerous Mitzvot and he heeded them all. Therefore, Avraham was a tikkun for the element of Adam’s not listening to G-d’s command.
As is pointed out by all the commentators, the Torah barely recounts the life of Yitzchak. This is because it was almost perfection. Think about Einstein’s famous formula E=mc2. It doesn't take up a lot of pages. We find Yitzchak often davening. He was fully pure. After Adam had his fall from grace, the kedusha in this world was contaminated. Yitzchak brought back that kedusha.
The Zohar notes that one of the satanic angels took control of the snake to encourage Chava to err. After succeeding, the poison of the snake entered Chava and then became mixed in with the future births of Adam and Chava. The birth of Yaakov and Eisav was a replica of this experience. Eisav was the manifestation of tumah from the snake while Yaakov was G-d’s ambassador in this world (as his face exists under the throne of G-d, and he represented emes just as G-d’s signature is emes). This is why Yaakov has to fight Eisav’s angel. This angel was representative of the original angel that controlled the snake that tricked Chava. Yaakov’s calling was to be a warrior. In this parsha it says Vayetzei, connoting a going out by free will. Yaakov, out of his own free will, went to battle Eisav. The only way to beat Eisav, the yetzer hara, is to conduct a free-will battle, and then G-d will deliver him. And though Yaakov achieved great strides in his battles, he was still scarred from the battle. That is why Yaakov represents Ma’ariv, because it’s a reshus to battle the yetzer hara and also because Ma’ariv represents galus and darkness, which still remain.
In the Ushpizin prayer on Sukkos, we invite the avot and great leaders into the Sukkah. One of them is Dovid. Dovid took 70 years from the perfection of Adam HaRishon. Therefore, only Dovid's progeny will be able to restore perfection to the world, and G-d will ultimately slay the yetzer hara. However, the three avot were the ones who set the stage for this ultimate perfection.