Bhakti-yoga is the sunlike illumination for delivering the conditioned souls, whose general condition is described here. They have no eyes to see their own interests. They do not know that the goal of life is not to increase the material necessities of existence, because the body will not exist more than a few years. The living beings are eternal, and they have their eternal need. If one engages only in caring for the necessities of the body, not caring for the eternal necessities of life, then he is part of a civilization whose advancement puts the living entities in the darkest region of ignorance. Sleeping in that darkest region, one does not get any refreshment, but, rather, gradually becomes fatigued. He invents many processes to adjust this fatigued condition, but he fails and thus remains confused. The only path for mitigating his fatigue in the struggle for existence is the path of devotional service, or the path of Krishna consciousness.
(Srimad Bhagavatam - 3.29.5)