Many of us have suffered trials and tribulations during our life. There is no 'right ' way of dealing with life’s hardships, and for some it leads to genuine doubts about G-d’s existence, being that if G-d really existed, we may assume He surely would not allow for such injustice to take place. The question is a real one, but the logic behind it is faulty. I often get questions about how can one believe in G-d after the Holocaust. It's probably Rabbi101 for most of us and each Rabbi develops his own answer, hopefully being sensitive to the person and circumstances the question is coming from. If the situation lends itself, I often try to explain that the question mixes apples and oranges, and the conclusion has nothing to do with the question. G-d's existence, or lack of it, cannot be dependent on how G-d does His job, or how well we understand His actions in the world. If that would be the case there would be very few believers.
Whether He exists or not cannot be based on how much we understand, on any particular day, of why G-d does what He does. G-d either exists or doesn’t, and this cannot change on the basis of how we wake up in the morning. The Torah gives G-d's credentials in the first sentence "in the Beginning G-d created the heavens and the earth" This is His introduction, and perhaps a measuring stick one can use to decide objectively, for yourself, if G-d exists. If we believe that the universe, in all its complexities and majesty, can come into existence and then exist on its own, then we have a real question as to G-d's role in all this. If, however, we believe that the universe must have a Creator, then our belief should be firm, even though our questions, and anger, may persist.
A crisis of faith as a reaction to events in life is really just a reaction to how G-d is doing His job. If somebody’s parents did a lousy job, or were even abusive, that person would never think of concluding that they don't have parents. They would question what kind of parents they have. Similarly, finding events in life repugnant, unjust, cruel or downright tragic, creates a question as to 'what is G-d thinking?’ It does not change the conclusion as to how the world is coming into being. It behooves a person to study the words of our Chassidic Sages who clarify the role of evil, injustice and pain in this world, and why G-d gave them such prominence.
However, while searching for answers that will satisfy ones challenges in life, one may still not be sure whether G-d exists and whether He gave us the Torah. Nevertheless, this should not stop one from observing Judaism in all its particulars.
The great Rabbis Maimonides and Nachmanides have a very interesting disagreement in their enumeration of the 613 commandments. Nachmanides counts the first Mitzvah as believing in G-d, while Maimonides lists "knowing G-d' as the first mitzvah, and nowhere mentions belief in G-d as a mitzvah. What is the basis of their disagreement?
Maimonides teaches that belief in G-d is central to the fulfillment of a mitzvah by nature. He opines that one cannot properly do a mitzvah if one doesn't believe in the commander of the commandment. Therefore the belief in G-d for Maimonides is the foundation of each of the 613 mitzvahs, and cannot be separated to become just one of them.
However, Nachmanides takes a more liberal approach, by counting belief in G-d as one Mitzvah. According to him, if a person does not believe in G-d they can still fulfill the other 612 Mitzvahs in their entirety.
This sends a very strong message! Many Jews struggle with a belief in G-d, but during this struggle they are still able to have a meaningful relationship with Judaism through the fulfillment of all the other Mitzvahs. This struggle may last years or even a lifetime, and take them to delve into the sciences as well as the Torah, to conclude if the universe has a Primordial Cause. But the search should not be a cause of holding us back from doing the other 612 Mitzvas - good deeds needed to make this world a better place. Hopefully, after a sincere search, ones conclusion will be an affirmation of G-d’s existence, and of the Giving of the Torah, and retroactively one will be very happy that they observed the Mitzvas, according to Nachmonides