A good thought
ובני קרח לא-מתו
And the sons of Korach did not die
Parshas Pinchas contains yet another census. The Torah lists all the different families by tribe and states their total numbers. In the midst of this listing, the Torah mentions the family of Korach, the one who started a failed rebellion against Moshe. The Torah wanted to emphasize that although Korach’s children were part of his rebellion, they did not perish like their father did. Rather, they had thoughts of repentance, and Hashem spared their lives.
Now, it is known that there are four prerequisites to proper repentance: (1) stopping the sin (2) regretting the sin (3) verbally admitting the sin (4) committing to never transgress the sin again. What’s interesting to note is that we aren’t informed that the sons of Korach fulfilled these requirements. All that is mentioned is that they had thoughts of repentance. Apparently, this was enough to merit salvation.
We see from here the tremendous power of a good thought, as long as it’s genuine. We are taught that a person can acquire their eternal reward in a single moment. A person can go from a completely wicked person to a completely righteous person in an instant. Where else do we see this? Our Sages tell us that if a wicked person betroths a woman on condition that he is completely righteous, we treat them as married. We are concerned he had thoughts of repentance, and his condition was fulfilled. It sounds like thoughts of repentance alone can make all the difference. The same held true for the sons of Korach.
 Based on Ayeles HaShachar to Numbers 26:11, by Rav Aharon Leib Shteinman
 Numbers loc. cit.
 Cf. Targum “Yonasan” ad. loc.
 Rashi ad. loc.; Although Sanhedrin 110a implies they merely survived in Gehenom, see Rashi ad. loc., Rashi to Psalms 42:1, and Maharal in Chiddushei Aggados ad. loc.; Cf. Gur Aryeh ad. loc. § 8
 HaEmunos V’HaDeos 5:5 by Rav Sa’adiah Gaon; Mishneh Torah Hilchos Teshuvah 2:2. See Pachad Yitzchak Yom HaKippurim 21:16 regarding the dispute between the Rambam and the Sha’arei Teshuva
 Avodah Zarah 17a
 Kiddushin 49b
 Cf. Minchas Chinuch § 364