Franz Rosenzweig begins his The Star of Redemption by stating that death is an overshadowing concept that is so present in our consciousness that, paradoxically, death is part of life. This always struck me as very dated. Sure, during World War I, with war and disease on all sides and people dropping like flies, people were constantly scared of dying. But in today's world (at least in US), who thinks of dying? Between hygiene, medicine and the general comforts of life, death is not by any means an overshadowing concept.
R. Mayer Twersky suggests that it should be. That, he explains, is why the Torah ends with death - Moshe's death.
The Torah is underscoring a fundamental, indispensable perspective on life. We must live our lives with a keen awareness of our mortality. This perspective ought to be sobering and energizing, not depressing or paralyzing. Armed with this perspective, we are able to establish and maintain correct priorities. Since olam ha-zeh is simply a gateway to olam ha-ba ("olam ha-zeh resembles a corridor before olam ha-ba. Prepare yourself in the corridor so you can enter the banquet hall" Avos 4:17), it is the ultimate folly to pursue physical pleasures and material possessions. "Fear not when a man grows rich, when he increases the splendor of his house. For upon his death he will not take anything, his splendor will not descend after him" (Tehilim 49:17-8). By dint of nature and nurture, we always plan for the future. We prudently establish pension plans, invest in IRA's, etc. But the ultimate and eternal future is olam ha-ba. Are we equally prudent in prioritizing and planning for that future? We can only hope to answer the question affirmatively if we maintain a perspective of mortality.