Rabbi Yakov Haber
The Enormous Effects of Human Action
"For all living creatures (lit. all flesh) have corrupted their conduct on the Land" (Noach 6:12). With this statement, the Torah explains one of the reasons behind the Divine decision to destroy the world through the Flood. As the commentaries quoting the Midrash note, "all flesh" refers to animals as well, who mated with species other than their own. Noting the abnormality of creatures operating based on instinct acting in this bizarre manner, the first Rav Yosef Dov Halevi Soloveitchik zt"l, in his work, Beis HaLeivi, presents a fundamental insight as to the effects of human action.
All of the creation was formed by G-d to serve as the environment in which Man would serve and connect to his Creator. When Man acts sinfully, he affects the entire world adversely. When he acts properly, he elevates the world and perfects it. Since Man did not uphold even the core morality commanded to Adam and his descendants concerning arayot, engaging instead in adultery, homosexuality and even bestiality, the animals acted in a similar way.
The Beis HaLeivi further elaborates that Man's actions directly affect other people's actions in two ways: directly, by serving as either positive or negative examples for others to copy, and indirectly, by introducing into the created existence positive or negative spiritual forces which affect others. Based on this, Rav Soloveitchik contrasts Noach with Avraham. Both were enormously righteous individuals breaking with the corrupt ways of the society surrounding them. However, Noach needed Divine assistance, not in initially choosing the correct path but in inoculating himself from the disastrous influences created by the surrounding society which would have ordinarily affected him as well. The only way to save the world was to destroy that society in order to eliminate its negative effects on even the righteous one of that generation. Because of this, Noach's merit could not save the world; the only way to protect him was to separate him into a teiva shielding him from the evil influence of the world. Avraham, by contrast, was able to remain upright without special Divine assistance, withstanding all of the direct and indirect influences of the surrounding society. Because of this, he did not have to be separated from them and they did not have to be destroyed.
Beis HaLeivi further explains the differing opinions quoted by Rashi concerning the word, "b'dorosav", "in his generations" (6:9). Reish Lakish states that even in his generations, Noach was righteous, all the more so if he were in the generation of Avraham. R. Yochanan states that only in his generation was Noach considered righteous. Had he been in the generation of Avraham, he would not have been considered righteous. All agree that Noach was a great tzaddik, choosing to cleave to G-d as the correct path. Had he lived in a generation of righteous people, he certainly would have been even more righteous because of his will to follow G-d. This point is made by Reish Lakish. But, in contrast to Avraham, he was not independently able to withstand the evil influences of his generation. This point is made by R. Yochanan. Their argument revolves upon which aspect is alluded to by the word "b'dorosav".
The Mishna in Pirkei Avot (5:2) speaks of the ten generations from Adam to Noach during which Hashem exhibited the quality of erech apayim, delaying his anger and punishment even though mankind was sinning, until He brought the mabul upon them. By contrast, the ten generations from Noach to Avraham are similarly described, but the Mishna ends with the statement that Avraham received the reward of all ten generations. Noach did not receive the reward of the generations before him. This is because Avraham, by remaining faithful to HaKadosh Baruch Hu in spite of the previous generation's influences without the need for special Divine assistance, earned increased reward for himself for each negative action performed by those generations.
The Gemara (Chagiga 15) states that the tzaddik receives both his share and his friend's share in Gan Eiden. The rasha receives both his share and his friend's share in Gehinom. This too, explains Rav Soloveitchik, is because the tzaddik has a share in others' good actions which he either directly inspired or indirectly caused as explained above. Therefore he receives reward for others' actions as well. With the rasha, the opposite is true.
Tosfos (Rosh HaShana 16b s.v. "l'yom hadin") state that the judgment of Rosh HaShana also concerns Olam HaBa. Rav Zev Leff, quoting others, explains that this is because mitzvos and aveiros "earn dividends". Each year the results of the particular person's actions in the world in terms of their effects on the current generation are re-evaluated, and consequently, the person's share in the afterlife is also affected.
May we merit to be inspired by these powerful words of the Beis HaLeivi to inject increased enthusiasm in performing Hashem's will, withstanding the trend of the world around us, elevating not only ourselves in the process but also, to some extent, the entire world.
 See also The Immense Effect of Mitzvot for a related
treatment of this topic.