The Midrash (Eichah Rabba 4:10) says that a merchant in Rome was selling a diamond. But the consumer wanted to test it, to be certain that it was a real diamond. So he put the diamond on a ledge and beat the diamond with a hammer. The ledge and the hammer broke and the diamond remained intact. That proved that it was real.
Tzaddikim explain that the same applies to emunah. How does one know that his emunah is real? When he endures beatings, and he still believes strongly and firmly in Hashem, this proves that his emunah is genuine and precious.
A Holocaust survivor was speaking against Hashem in front of the Chazon Ish. This survivor couldn’t make peace with the tragedies he witnessed. The Chazon Ish showed him a Tosfes and asked him to explain it. The man didn’t understand the Tosfes. The Chazon Ish told him, “If you don’t understand a few line of Tosfos, how do you expect to understand Hashem's ways?”
We say in Tehillim, בחכמה כולם 'ה מעשיך גדלו מה זאת את יבין לא וכסיל ידע לא בער איש ..עשית, “How great are your ways, Hashem.. A fool doesn’t understand them...” The pasuk says that the fools don't understand Hashem's ways. But, behold, also the wise and intelligent aren't able to comprehend Hashem's ways!
We can answer that the pasuk should be read like this: 'ה מעשיך גדלו מה, "How great our Your ways, Hashem... זאת את ידע לא בער איש, the fool, however, doesn’t know that Hashem's ways are deep. He thinks everything should be logical. And when it isn't, he asks questions on Hashem. The wise know their limitations of their weak minds, and they understand that they won't be able to understand all of Hashem's ways.
