Why does G-d allow us to doubt Him? Just a recommendation that if you have a Likurei Moharan, take a look at I:64, esp. since it ties in with the next parshiyos. I touched before on the idea of tzimtzum, which provides a solution to the problem of the inherent contradiction between G-d's infinite Being and creation as we perceive it. If G-d has no boundry and is a singluar indivisible "Being" which transcends space/time, how can I, an independent entity with free will, exist in a physical world at a specific point in space/time? Should not G-d's "infiniteness" of Being swallow me up or not allow me to exist at all? The idea of tzimtzum teaches that for physical reality to exist, G-d first created created an appearance of a Void (chalal panuy), a space that gave the illusion of being empty of His presence, and only through that can any separate universe come into being. At the same time, we believe paradoxically that G-d remained unchanged and fills all of reality. These ideas are diametrically opposed, yet exist simultaneously and are actually in harmony. This is what we discussed with respect to Yosef and Yehudah and Mikdash and Mishkan, the challenge of affirming the yichud gamur of Hashem's presence with us in every aspect of reality, and at the same time hidden from our view so we have free choice.
R' Nachman extends the cosmic idea of tzimtzum to the very personal level. The chalal panuy, the space that G-d created that seemed devoid of His presence, is not just the key to the cosmic idea of creation, but it is the key to understanding faith and doubt. Inside every peson there is a chalal panuy, a place where there exists some unanswerable doubt, some point at which G-d's presence seems absent. Many doubts are simply a product of a lack of knowledge, e.g. the entire internet debate of evolution and ma'aseh braishis is a product of our limited scientific wisdom and our limits of wisdom in understanding the Torah. The doubt of the chalal panuy is more profound - it cannot be solved by knowledge or answers. It's an existential doubt, not an epistomological doubt.
Our working assumption is that dibbur, speech, is the answer to doubt. You don't understand? Here are more words, more facts, more explanation. All that is fine when it comes to the doubt which is due to a lack of wisdom, but it utterly fails when the doubt is existential. I thought of a mashal that may help here, but feel free to critique it. Imagine little kids at a puppet show. Not knowing about ventriloquism or the control mechanisms, for all intents and purposes to the children the puppet appears to talk, to move, to be Pinnochio! Yet, the children know a puppet cannot be alive, so they ask the little puppet to explain how it works. No matter how many words the puppet speaks, it just cannot convince the children that it is not speaking. In fact, the more it speaks, the more it reinforces the illusion that it is in fact alive. The only thing that would immediately dispel the illusion is if the puppet master stood up from behind the screen, yet doing so would end all the fun of the show. The nimshal: to us, the world, with all its defects, seems to be running on its own course with no external control by G-d. Pinnichio is alive and kicking. The only way to really dispel the illusion would be for Hashem to remove the chalal panuy, to reveal that the puppet is just a an act, but to do so would end the universe as we know it.
Hashem created the world though 10 statements, through dibbur. Dibbur keeps the illusion going, it defines things in neat little boxes, and solves all the problems you give to the puppet except for the biggest problem of all, how the puppet works. The only way around that is shtika, silence, the silence of faith that behind everything G-d is in control. Moshe is "kvad peh", he finds speech difficult, because he knows that the G-d ultimately transcends all the words we utter - it all just boils down to faith before the Void. If the puppet master is in charge, why is there a wicked Pharoah killing Jewish children? The only answer Moshe and the tzadikim can give us is the strength to have faith. The existential question cannot be answered, for to do so, to reveal G-d's presence even in the chalal panuy, would mean the end of our existance. When G-d is asked to explain the suffering of R' Akiva and his horrible death, He answers "shtok", be silent. Pharoah, the chalal panuy, exists "lama'an shiti ososay eileh b'kirbo", so that the osos, literally the letters, the speech of G-d that created the Universe, can exist.
I don't think R' Nachman is saying you can't ask a question that there is no answer to. If you learn the Torah, R' Nachman goes on to say that the Tzadik (Moshe) can help with the doubt of the chalal panuy. This was the song of "az yashir", the song that tells us that all the answers in life are not things that can be expressed through speech or rationally understood. Silence is not avoiding the question, but serves as the answer. The answer to doubt is not always explanation, but sometimes is pure and simple faith. R" Nachman says only Moshe can approach Pharoah because for most of us, it is better to avoid doubt than to face it head on and try to overcome it through faith.
If you are a rationalist, this whole approach probably makes you very uncomfortable. A rationalist wants a logical way to explain away everything, and sees failure to do so as a weakness of reasoning ability, not a product of the human condition. The mystical approach of R' Nachman plants doubt as part and parcel of the human condition no matter how smart we are. I admittedly used to be more inclined to grapple with the things rationally, but I have moved more squarely into the R' Nachman camp on this one. I don't like kiruv programs that portend to offer answers to all the great questions of existance, or people who can rattle off reasons for the Holocaust in an evening's speech. Some mysteries are too profound for simple answers or essays, and the only real answer is the silence of faith.