The Alter Rebbe passed away on the 24th of Teves 5573 (1812), while fleeing from the onslaught of Napoleon, whom he opposed bitterly. His ohel
(resting place) is in the Russian town of Haditch.
Some of the most striking differences between Yiddishkeit and the non-Jewish way of life, are evident in the way the former approaches some of life's major events, such as birth, marriage and death.
How does a non-Jew look at death? To the non-Jewish way of thinking, death means that life is all over. A person lived, and then he died, and now it's all over. Yiddishkeit, and particularly Chassidus, maintains that death is the point at which all the mitzvos which a Jew has accumulated throughout his life reach their culmination and peak. As long as a Jew is alive, every day, every hour, every minute he adds to the sum total of his mitzvos. In some cases this can even be without his being aware of it. This principle applies even to those who are not yet observant -- as our Sages state, "Even sinners among the Jewish people are as full of mitzvos as a pomegranate is full of seeds."
The minute a person passes away from this world, he is no longer able to do any more mitzvos, and therefore he has reached the culmination of his life on earth at that point. But what about sin? Don't his sins erase the effect of his mitzvos? The answer is that they do not. Mitzvos are eternal, and therefore cannot be "cancelled out," even if there may be sins which have to be accounted and atoned for.
Although the soul existed up in Heaven before its descent into a body in this world, its powers and identity are concealed. When the person is born in the world, his soul begins to operate and shine in a different way, in a revealed way. And therefore the soul is compared to a candle, for it too illuminates the world.
Now, on the day of a person's passing, and especially so regarding the passing on of a tzaddik, whatever that person did in his life, and whatever he worked for, from the moment of his birth until the point of the departure of his soul from his body, becomes revealed and illuminates the world from Above in a tremendous burst of light, which is the sum total of whatever that person achieved in his life. Obviously the greater the person, and the more he did in his life, the greater is the light at the moment of his departure. So it's a very very special moment. The death of a person is a special part of his life. And from that time on, every year on the day of his death we again recall that person and what he meant for the world, and in this way his light shines even more brightly.
Of course, our physical eyes cannot see this -- but what the deceased person achieved does not disappear the moment the body is buried. It's true the body may no longer be there, but the soul of the person continues to exist, and is still connected to the body in the grave. We are able to receive some of the radiance of this soul's light by davening at the graveside, as is explained in Chassidus, in a discourse of the Mitteler Rebbe. And this is the reason for visiting the grave of the person, and particularly the resting place of a tzaddik.
It is a fundamental belief in Yiddishkeit that the connection between the living and the dead is not interrupted, particularly as regards a tzaddik. On the contrary, one of the tenets of Chabad Chassidus, based on statements in the Zohar, is that a tzaddik can do more for his people after he dies, than while he's alive. After his passing from this world, he is liberated from the restrictions of the physical body, and in a sense his neshamah is even higher and closer to HaShem. So if we need someone to intercede on our behalf, we should definitely daven at the graveside of a tzaddik.
Every person has hidden inner strengths or powers. When life is nice and easy, we do not activate these hidden powers. But in the times of galus (exile), because we do not see overt miracles, and the Shechinah (the Divine Presence) remains hidden from us, our Jewishness has to come much more from the inside, so that our inner powers become revealed. And that is why, throughout the Galus, Jews have always demonstrated mesirus nefesh -- self-sacrifice and martyrdom, which stem from the activation of these hidden inner powers of the soul. We saw times when Jews were slated to be killed, times when they were discriminated against, times when logically you should say, "Well, now they are going to stop being Jews." But they fought and they brought out their connection to HaShem from deep within themselves, from their very essence.
You can see an example of this in the relationship between a husband and wife: Although they obviously care for each other, since they see each other every day, this deep, caring feeling is not evident on the surface. But when there's a separation and they are far away from each other, then the bond between them becomes revealed. You know, just like when your husband had to go to America for three weeks, then it's, "I'll never scream at him again for the rest of my life." It's only when you're far away that you feel how important it is to be loving and considerate, right? When do you feel these feelings? When you are separated for a while.
This is the nature of galus. As David HaMelech said in Tehillim: "Tzamah lecha nafshi, kama lecha besari..." -- "My soul thirsts for You; my flesh wilts for You." When? Precisely "in a thirsty and weary land, without water." When you are far away from G-d, in exile. When Mashiach comes, we will say, "What idiots we were! We did not take advantage and now it's too late!" In other words, in galus we have opportunities to develop that don't exist when we are not in exile. This is the unique quality of galus and its purpose -- to bring out these hidden powers in order to overcome the darkness. It takes great inner strength to say, "I don't care if you don't like me," and "I'm going to defy the non-Jewish way of life." It's hard to say, "I'm a Jew." But this is the ultimate purpose of galus, and even though all of us would be willing to forego this for the immediate Geulah, this is apparently not what HaShem has wanted up until this very moment. May Mashiach come very, very soon!