Rabbi Nachman teaches,
There are people who sleep away all their days. Some have fallen into their sleep on account of lust and wrongdoing. There are other cases where truly good people of beautiful character fall because of food. A person may sometimes consume food that is insufficiently pure to be fit for human consumption, and his mind then falls into a kind of “sleep”.
When a person eats in holiness and purity, his physical face and the inner “face” that is his soul become radiant as a result. But if he eats without holiness, the food harms his heart causing him to lose this inner face, so that he falls into a “sleep”. He may still imagine he is serving G-d, occupied as he is with Torah and prayer. But he is “asleep” in the sense that his devotions remain in the lower worlds and G-d has no delight in them.
It is vital to rouse such people from their sleep, but this is only possible if they first begin to stir on their own. The tales and stories told by the Tzaddikim have the power to rouse those who are asleep so that their days will not be wasted. It is a great privilege to find a Tzaddik who has the power to rouse you from your sleep. Otherwise you could sleep away all your days, G-d forbid.
Likutey Moharan I, 60
With permission taken over from: Daily Dose Of Rabbi Nachman