A common theme of Judaism is that the current life we live is the physical portion of our lives. We hold the concept of Olam Haba as the world to come, where we see the repercussions of our actions and ultimately become responsible for them. There is a famous story of a rich man who came to the Chafetz Chaim's house for a blessing. Upon entering, he couldn't help but notice the lack of furniture in his house. Finally the rich man could no longer contain himself. "Where's your furniture?" he asked. To the rich man's surprise, The Chafetz Chaim responded with another question. "Where is yours?" he asked. "I don't need any furniture" replied the visitor, "I'm just passing through." The Chafetz Chaim smiled and explained to the rich man that in this world we too are "just passing through."
The life we have is only a blink in time, and we must make the best of it. The more we do in the short while we have on this earth, the higher level we will reach in Olam Haba. People who realize that life is so short try their hardest to make the most of their lives, trying to impact others as much as possible.
One of our great ancestors that impacted the Jewish people as a whole was Moshe Rabeinu. In B'midbar 3:1 we are informed "Eileh Toldot Aharon U'Moshe", yet the next few Pesukim only mention Aharon's sons. The obvious question can be asked: Why Does the Torah say that Aharon's sons belong to Aharon and Moshe? The Talmud provides the explanation that one who teaches Torah to someone else's children is considered their parent. When a person teaches Torah, as well as does any Mitzvah for another individual, a special link is established. We learn that after the Eigel HaZahav, Moshe prayed for Aharon's two sons Elazar and Itamar to be saved. In addition, Rashi and Ramban comment that because Moshe taught Torah to Aharon's four sons, he became their spiritual father just as Aharon was their biological father. From this we can derive that any time the word of Torah is passed down from mouth to ear, from teacher to student, a bond is not only formed between the student and the Torah, but also between the student and his teacher. So too, when a Mitzvah is done from one person to his fellow man an unbreakable bond is formed not only from one man to the other, but also from each man to Hashem. The way Moshe impacted the sons of Aharon made it so that his relationship with them was not only as a friend, but equal to Aharon's relationship to them as a father.