(As a “junior” in a NYC public high school years ago, I was required to read Voltaire’s “Candide.” It’s a short novel, written by a genius, undermining any certainty we can have that G-d is good. It’s fair to raise the question — sooner or later, life itself forces us to do so. But when we read it, we weren’t given any alternative viewpoint or argument. We would have needed to hear a “voice” as confident in its belief as Voltaire was in his. For example, we might have been required to read the letter (below) by the Lubavitcher Rebbe, z”l, for an “answer” to Voltaire’s view. Young minds are impressionable. I was actually very impressed by “Candide” when I read it. It took me 10 years or more to even begin to find my way back to belief. And even that was only a first step. The Rebbe’s answer is very much like the ultimate argument in “Job,” but briefer and simpler. His personal conviction is its greatest strength.)
Can We Understand G-d? 
By the Grace of G-d
16th of Kislev, 5725
[November 21, 1964]
Dr. Pesach Gedalia Mann
I am in receipt of your letter of November 11th. No doubt my letter of condolence was duly received by your family. May G-d grant that from now on we should only have good news to write to each other, and none of us should know of any sorrow in the future.
I can well understand your feelings under the stress of your great loss. However, as has been explained in various holy sources at length, and reflecting upon the infinite difference between the wisdom of the Creator and the human capacity for understanding, etc., it would be more surprising if a human being could understand, at all times, the ways of G-d. It is only because in His Infinite kindness G-d desired that some of His ways should be understood occasionally, that we get an insight now and again into the ways of G-d.
Yet, if we contemplate the extraordinary order and precision that exist in nature, even in the lowest created forms, namely inanimate things (the harmony and energy of the atom, etc.), all of which are the opposite of chaos and disorder, this surely supports the simple faith that Jews have in the goodness and righteousness of the Creator, whose benevolent Providence extends to everyone individually. If we cannot expect a small child to understand the thinking of a profound scientist, although the difference between them is only a relative one, inasmuch as the child might someday become as great or perhaps an even greater scientist, it should certainly not baffle us that we do not understand the thoughts and ways of G-d, as indicated above.
I want to emphasize here one more point. The soul is of course eternal, for it is only the body that is subject to decomposition. Therefore, death can only terminate the physical and earthly aspects, while the soul passes on to a higher life. Hence all the things which would have brought spiritual gratification to the soul during her lifetime on this earth can still bring that gratification to the soul, and even more, and it is up to the children to continue to do so. Having met your mother when she was here, and knowing of the background of your family, I am sure that I do not have to remind you about Kaddish, Mishnayos and Tzedoko, as a source of gratification for the soul of your departed mother. But every additional effort in all matters of Torah and Mitzvoth in the daily life, permeated with Chassidic warmth, is a source of everlasting gratification to her soul.
With regard to the special Mitzvo which you undertook for the soul of your mother of blessed memory, namely a selection of Tehillim, you should, of course, continue to keep it up. In addition to this, however, and in view of the fact that the soul is that of a woman, it would be well to make a special effort in the area of Mitzvoth which are of particular concern to Jewish women, and of particular importance in this day and age. I have in mind the effort to strengthen and disseminate the matter of Taharas Hsmishpocho, or the like.
(Rabbi Menachem Mendel Schneerson)