Rashi cites Chazal, who differ in opinion regarding Noach’s level of righteousness as compared to Avraham. Some Rabbis explain the phrase “in his generations” to Noach’s credit i.e.; his righteousness would be noteworthy all the more so had he lived in a generation of righteous people. Others feel that had Noach lived in Avraham’s era, in contrast he would not have been notable at all. Rashi’s statement, which presents Noach as having had no relative importance, seems to be a bit critical. True, he would not be as great as Avraham, but he was nonetheless still a great tzaddik!
Rabbi M.Z. Bergman, Shlita, offers the following response. He cites the Midrash in Shir Ha’Shirim, which quotes the following parable. A king once lost a precious diamond in the dirt. He took a sieve and sifted through the dirt until he finally succeeded in locating his diamond. Likewise, Hashem sifted through the early generations of leaders which preceded Avraham and cast them away until He found Avraham. This happened once again in His search for Dovid Ha’Melech. From Peretz through Nachshon until Dovid, all were viewed as relatively insignificant until Dovid was located. This analogy is puzzling. Are we to relegate such tzaddikim as Shem, Ever, Nachshon, Boaz, Yeshai, to nothing? Just because they did not attain the sublime level of Avraham or Dovid are they to be discarded?
Rabbi Bergman explains that we are identifying various levels of spirituality. Every rung represents another level of eternity. One cannot compare spiritual accomplishments which effect a reward of an unlimited eternal nature. This is an amazing statement. Imagine if one were to study one more blatt, folio, of Talmud or even one more pasuk in Chumash. He is not just a greater scholar; he has actually attained a much greater level of eternity. The individual is no longer the same. Undoubtedly, Noach was a great man. Had he lived in Avraham’s generation, however, his spiritual accomplishments would have paled in contrast to those of Avraham Avinu.