Avos chapter 4, mishnah 19 (in some versions: mishnah 15). Before us are the words of Rabbi Yannai, the father of Rabbi Dosa who is mentioned in the third chapter, mishnah 8. This mishnah is almost everything we know about Rabbi Yannai, and yet in it he raises a point that has troubled every believing person since time immemorial: why do the righteous suffer, and why do the wicked prosper, at least at times.
The talk show host Dennis Prager put it very wisely: "The believer in G-d has to explain the existence of undeserved suffering; the atheist has to explain the existence of everything else." It is indeed a problem - there may be greater problems than it, but this is a central theological and philosophical problem: why do bad things happen to good people, and why are there seemingly bad people whose lives are comfortable and successful? The answer is complex.
The wording of the mishnah:
"Ein b'yadeinu lo mi'shalvas ha'reshaim v'af lo mi'yissurei ha'tzaddikim" - "It is not in our hands," meaning the matter is not within our reach. We do not have the ability to arrive at a complete answer to the question of why the wicked sometimes merit tranquility and calm in this world, and likewise why the righteous suffer afflictions.
Certainly there are partial answers, and many answers have been offered on the subject and much ink has been spilled over it, and it is not our intention to discuss all the approaches. The Gemara in Berachos daf 7 deals with this explicitly, and every great thinker has had to grapple with this question.
The question in the words of the prophet and in the words of Moshe Rabbeinu:
The mystery is already expressed in the words of Yirmiyahu the prophet himself: "You are righteous, Hashem, when I contend with You, yet I will speak judgments with You: why does the way of the wicked prosper, why are all the treacherous ones at ease":
"Tzaddik atah Hashem" - a full acknowledgment of the righteousness of the Holy One, blessed is He.
"Ki ariv eilecha" - and nevertheless I have a complaint against You.
"Ach mishpatim adaber osach" - I wish to discuss the policy by which the world is run.
"Madua derech reshaim tzaleichah" - how can it be that the way of the wicked succeeds?
"Shalu kol bogdei vaged" - and why do treacherous people merit tranquility and peace?
So this is an ancient question. And if Yirmiyahu the prophet did not have the answer, neither do we. Moreover, the Gemara in Berachos daf 7 says that even Moshe Rabbeinu, when he asked "Make Your ways known to me," was asking to understand this very question. This question, then, troubled Moshe Rabbeinu as well.
I do not have the answers. In the past I served as a tour guide in Poland for high school age youth, and without exception, when studying the Holocaust the question comes up: "Where was the Holy One, blessed is He? How could He let these things happen?" My standard answer was: "I have no interest in ruining a good question with a bad answer." The matter is complex. There are some answers, and I am not saying that there are no answers at all.
The main point of Rabbi Yannai's words:
The point in our mishnah is that the complete answer, the fully satisfying one, the one that would explain each and every case, lies beyond our ability to grasp. The Rambam himself states this, and all agree to it: part of reality is reserved to the credit of the Holy One, blessed is He, in the way that He runs things.
And yet, there is no doubt that in the end we will know why it was just. We believe with complete faith in "Keil emunah v'ein avel" - that the Holy One, Blessed is He, is worthy of our trust, and does nothing that is not just and fair, "tzaddik v'yashar Hu". But that does not mean that it will necessarily be revealed to us, at this point in time, how and why He does what He does.
In summary: Rabbi Yannai teaches that sometimes several answers can be found, but ultimately "ein b'yadeinu" - we do not have all the answers, and some of them must be accepted on faith. With Hashem's help, in the end we will have the answers, and we will understand why the Holy One, Blessed is He, did precisely what He did. That understanding is a necessary part of the process by which history unfolds toward its conclusion - in the end of days, in the times of Mashiach and afterward.