The end of Parshas Bereishis lists the generations from Adam until Noach. The Torah prefaces this list with the words, "Zeh sefer toldos ha'Adam - This is the account of the offspring of Adam" (Bereishis 5, 1). The Ramban comments that aside from the simple meaning of the words, there is another explanation. The word "sefer" mentioned in the above pasuk is not merely referring to the genealogical account recorded in the ensuing pesukim, it also refers to the book of the Torah in its entirety.
Rav Wolbe (Shiurei Chumash) elaborates on this idea. Most people live their lives without putting much thought into their behavior. Their thoughts, actions and speech are "hefker" and they are the results of their whims. In contrast, one who learns Torah is affected so profoundly that his very essence and conduct change for the better. As the Rambam writes (Hilchos Da'os 5. 1), "A Talmid Chochom is distinguishable by his actions, his speech and his manner of walking." It is the Torah that is responsible for this enhancement of one's personality.
While gentiles are awed only by one who erects a colossal building or founds a distinguished organization, the Torah teaches us that our awe should be reserved for different accomplishments. Overcoming a test and conquering one's yetzer hara, or correcting a negative middah is something which should be truly awe inspiring! The Torah teaches us the greatness man is capable of reaching: "This is the book which describes the offspring - accomplishments - of man."
Since man's true essence is defined by the Torah, every mitzvah or aveirah affects the spiritual makeup of his body. There were great people who were able to discern which averiah others had transgressed. The Arizal once told a disciple that he had transgressed the aveirah of causing pain to an animal. Indeed, the disciple had eaten before he fed his animal violating the halacha that mandates that a person feed his animal before partaking of his own meal. When the disciple later stood before the Arizal after having rectified his misdeed, the Arizal mentioned that it was noticeable that he had rectified the aveirah!
Reb Yerucham Levovitz would cite another example of where the greatness of man is clearly discernable. In Parshas Matos the Torah describes at length the halachos pertaining to one who makes a neder (vow). It is simply mind boggling that a human being has the ability to forbid something upon himself through his speech in a manner that is just as binding as any other mitzvah written in the Torah and commanded by Hashem Himself!
As we begin a new cycle of parshios, let us bear in mind the purpose of the Torah. Every aspect of the Torah has the ability to affect some facet of our lives. Through learning Torah, slowly but surely, all our mannerisms will change for the better and people will declare, "Praiseworthy is his father who taught him Torah, praiseworthy is his Rebbi who taught him Torah (woe unto those who haven't learned Torah). Look how beautiful are his ways and how proper his actions!" (Yoma 86a).