Why does the Torah see fit to describe the men of Sedom here?
Rashi #1: To teach us that in spite of their perverted ways, Lot did not refrain from going to live with them. 1
Ramban: To teach us how HaSh-m protected Avraham from living among such wicked people. 2
Mishnas R. Aharon (Vol. 1, p. 147): This is the opposite of the ways of fear of HaSh-m. Therefore, Lot was not saved in his own merit. Chochmah u'Musar (Vol. 2, p. 326) writes, we do not find that Lot sinned in Sedom. Rather, just because he was not concerned lest he learn from them, he is considered a Rasha!
Chochmah u'Musar (Vol. 2, p. 371): How does his name rot? Nothing is more putrid than disgrace written in the Torah, aside from the punishment for the Aveirah.
What is the difference between "Ra'im" and "Chata'im"?
Rashi: They were evil (Ra'im) - with their bodies; and sinful (Chata'im) - with their money.
Targum Yonasan: "Ra'im" - with their money towards one another; " Chata'im " - with their bodies, regarding adultery, murder and idolatry. 1
Why does the Torah add "La'Sh-m, Me'od"?
Rashi: To teach us that their behavior was not based on ignorance; rather, "They knew their Master, and sinned against Him with intent." 1
Compare to Rashi to 10:9 (regarding Nimrod).
The verse condemns the Sodomites as evil and sinful. How can we explain Chazal's description of their attitude as mere unwillingness to share, "What's mine is mine, and what's yours is yours!" (Avos 5:10)?
Maharal (Nesivos Olam, Gemilus Chasadim Ch. 5, p. 164): If a person begins by standing upon the letter of the law and not giving in, eventually he will forcibly take anything he thinks might be his. Once used to doing this, he sinks to outright violent robbery. Maharal further explains that because they perverted their sense of "justice" into evil, they too received strict justice. Unlike the generation of the Flood which was punished with water (which had they repented at the last moment, would have turned to beneficial rains - Rashi to 7:12), Sedom was punished straightaway by a rain of fire and sulfur (19:24). 1
This must be reconciled with Gur Aryeh to 19:24, where Maharal writes regarding Sedom as well, that the preceding rain was to give them a chance to do Teshuvah. (CS)
QUESTIONS ON RASHI
Rashi writes: "They were Ra'im with their bodies, and Chata'im with their money." There are sources that explain in the reverse order (e.g. Targum; see Sanhedrin 109a).Why then did Rashi choose to explain this way?
Gur Aryeh: Some apply the word "evil" (Ra'im) to money matters, because monetary sins are due to jealousy (Ra Ayin) of other people's property. Rashi favors the interpretation of Rav Yehudah (Sanhedrin ibid.) that "evil" is an all-encompassing term, whereas "sinful" means in one regard. 1
See Maharal (Chidushei Agados, Vol. 3, p. 262-263, to Sanhedrin 109a) for an explanation of these two approaches. See also Nesivos Olam (Gemilus Chasadim Ch. 5, p. 162).