The exchange between Yaakov and Eisav regarding the sale of the bechora (rights of the firstborn) raises many questions. There are different opinions as to whether the sale related to financial rights in Yitzchak’s estate (Rashbam, Ibn Ezra), rights to lead in the service of Hashem (Rashi), or some type of undefined prominence (Ramban). There is also disagreement as to whether the meal Yaakov served was the whole payment, or whether Yaakov paid money and the meal confirmed the deal.
In any case, Eisav said that he did not value the bechora because he was to die and finally disgraced the bechora (Bereishit 25:34). Midrashim say that he denied techiyat hametim (resurrection of the dead). Where do we see this denial? If we follow elements of Eisav’s life, we find a preoccupation with the present and a disregard for that which happens after death. Chazal tell us that the day of the sale was the day that Avraham had died, at which time Eisav started sinning seriously (see Rashi to 25:30). Respect for his illustrious grandfather may have kept him somewhat in check, but with his burial, Eisav felt freer to sin. Later on in the parasha, we find Eisav wanting to kill Yaakov but only after Yitzchak dies (27:41). In other words, he wouldn’t want to cause pain to his father, but after he dies, "what he doesn’t know doesn’t hurt him."
This attitude may explain other things regarding Eisav’s behavior. Taking Rashi’s approach to the bechora, for example, Yaakov wanted to bring korbanot in the Beit Hamikdash. Of course, Yaakov never got to that, as such avoda was hundreds of years away. Eisav remarked: what do I need rights to things that will reach fruition after I am dead? Yaakov’s concern was for his legacy, whether it would be carried out by himself or by his offspring. Yaakov used this distinction to calm Eisav later. Upon meeting, as Yaakov returned to Canaan, Yaakov pointed out that he did not seem to have benefited from his father’s blessing of the fats of the lands and the dew of the heavens (see Rashi to 32:6). Yaakov knew that the blessing would find expression centuries later in the nation that bore his name, but he knew that Eisav was not moved by the future. Eisav’s focus on the present can also explain Yaakov’s use of the word "kayom" (like today) regarding the sale. "From the perspective of today, Eisav, it is a good tradeoff."
This is perhaps the idea of denying techiyat hametim. Techiyat hametim is not just a question of whether something new and miraculous will happen in the future. It is also about whether a person should care what happens to him after he dies. Will he "live" to see, both physically and spiritually, nachat from what he passed on to his children, after his death. For us, the investments that our forefather, Yaakov, made on our behalf are still paying large dividends. Our distant cousins did not merit the same concern from Uncle Eisav.