In Parashat Korach, Moshe announces to Am Yisrael how they will know whether he or Korach is correct. Moshe says, “ViIm Beriah Yivrah Hashem,” “And if Hashem creates a new happening” (BeMidbar 16:30). Why did Moshe require a new type of penalty to punish Korach? Were the previous punishments that were administered to sinners insufficient?
The Malbim answers that a large miracle, such as a new event that has never been seen before occurring, the Earth opening up and swallowing sinners, was required in order for Bnei Yisrael to have complete Emunah in Moshe as their leader and in Hashem. When Bnei Yisrael left Egypt, everyone accepted Moshe as their leader, but when Korach came and challenged Moshe’s legality he opened the door for others to do so as well. If others were able to challenge Moshe’s authority as well, then they would start challenging the Torah and eventually reject it. Therefore, similar to Yetziat Mitzrayim and Matan Torah, where Bnei Yisrael accepted Moshe and the Torah he heralded, there were great miracles, so too by Korach Hashem created a new type of punishment in order to keep Bnei Yisrael’s faith strong.