The power of the congregation and the sin of lashon hara

In our parashah, all of Bnei Yisrael are called an eidah (congregation), but the slanderous spies are likewise called an eidah. From here the Sages derive that an eidah consists of ten people, since there were ten spies. Similarly, in parashas Korach, the rebels are called an eidah. However, both the spies and Korach's followers are called an eidah ra'ah, an evil congregation, teaching us the tremendous power of a congregation to influence both for good and for evil. The spies spread lashon hara to the entire congregation, and the congregation accepted their words. Lashon hara is a grave sin, and once it spreads among the masses it can no longer be retrieved. Here, however, the sin was even more severe. The spies disparaged the land promised by Hakadosh Baruch Hu, denied Hashem's ability to protect them, and caused a chilul Hashem (desecration of the Divine Name), a sin that is not fully atoned for through repentance, Yom Kippur, and suffering alone, but only through death (see Rambam, Hilchos Teshuvah 1:4).