“The [Lubavitcher] Rebbe [z”l] said that after the Holocaust there were certain religious leaders who requested that his father-in-law, the sixth Lubavitcher Rebbe, join them in coming out with a harsh proclamation against those who voiced doubts in G-d following the Holocaust. The Sixth Rebbe was vehemently opposed, ‘…because there is a place, especially for the complete believer, to express his lack of understanding, and he has full permission to challenge G-d and ask, ‘How could You do this?'” 
I recently read an article by a well-known rabbi about the tragic deaths of seven young children in a fire in the house of an Orthodox family, using the same reasoning: Judaism allows — even encourages — us to “argue” with G-d. As an example, he cited Avraham arguing with G-d about the destruction of Sodom, as an alternative to Avraham’s accepting G-d’s Will in that matter.
I deeply disagree.
I believe that the ultimate goal of Judaism — as with Christianity, Islam and other religions — is for us to accept G-d’s Will.
It might be valid, though, to say that Judaism recognizes the human tendency to “argue” in the course of eventual acceptance. Debate, protest, even non-compliance, might be necessary steps in adjusting ourselves to things, even tragic ones, that we cannot ultimately change. Even the person who outwardly expresses acceptance is likely to require a prolonged time to fully surrender the heart. Torah allows for a human expression of outrage. It can be there, especially at first, whether we declare it or not.
And of course, we should never insist that someone who is going through such heartbreak “just have faith” unless it will be helpful for them to hear that. Compassion usually requires that we be far more sensitive to their feelings.
But this is a concession to human nature, not the spiritual goal itself. To say, or understand, that Torah permits us to “argue with G-d” as our only response to tragedy would deprive us of the very peace that our heart seeks most.
In this context, the Rebbes’ comments are better understood.
Questioning G-d is an acceptable beginning to a process that should culminate in our harmonizing ourselves with G-d.
If arguments between two people ideally tend towards resolution, kal v’homer (reasoning from lesser to greater), so should our “arguments” with G-d.
If we look with sadness at two people who have been unable to resolve their argument, kal v’homer, so should we look on one who has not been able to come to resolution with G-d.
The peace of faith isn’t gained by reasoning, anyway. It is the step beyond reasoning. Or, perhaps, one might call it a step without reasoning. The mind’s ability to reason has its purposes. Finding faith in G-d isn’t one of them, although some reasoning might lead to the eventual step beyond intellectual understanding.
It’s also true, of course, that this must be a thorough step. To “go beyond the intellect” without having resolved our feelings can tend only to suppress or obscure them. The price for that is that they’re still there, paining us without our full awareness of what the pain is or where it’s coming from. Such pain can manifest as headaches or other bodily pains, as interruptions in normal physical or cognitive functioning, as depression or other emotional disquiet; even as illness. But it will — sooner or later — be expressed.
Prof. Emil Fackenheim even proposed a “614th mitzvah” after the Sho’ah, the 4th part of which “forbids” us “to despair of the G-d of Israel, lest Judaism perish.” 
Note: he affirms that trusting G-d is essential to Judaism itself.
We don’t need to know why G-d does whatever is done, any more than a young child needs to understand why his/her parent does what they do.
The peace of G-d
opens to us
when we leave
our demand to understand