Which Test is Harder Than the Test of Emunah?

"AND MOSHE WAS VERY WROTH AND HE SAID TO HASHEM: DO NOT TURN TO THEIR OFFERING" (Bamidbar 16:15))

Here we learn an invaluable lesson: Not as is generally thought by most men, that if they would be convinced of the truth by open miracles, they would surely be perfectly righteous men. But here we see that even more than the test of belief in Hashem and in His management of men's lives, there is a still more difficult test of overcoming one's own character-traits such as jealously and the desire for glory. -- Journey into Greatness