When the purified senses are employed in the service of the Lord, one becomes situated in bhakti-rasa life, and any action performed for the satisfaction of Kṛṣṇa in this transcendental bhakti-rasa stage of life can be relished perpetually. When one is thus engaged in devotional service, all varieties of rasas, or mellows, turn into eternity. In the beginning one is trained according to the principles of regulation under the guidance of the ācārya, or spiritual master, and gradually, when one is elevated, devotional service becomes automatic and spontaneous eagerness to serve Kṛṣṇa. There are twelve kinds of rasas, as will be explained in this book, and by renovating our relationship with Kṛṣṇa in five primary rasas we can live eternally in full knowledge and bliss.
The basic principle of the living condition is that we have a general propensity to love someone. No one can live without loving someone else. This propensity is present in every living being. Even an animal like a tiger has this loving propensity at least in a dormant stage, and it is certainly present in the human beings. The missing point, however, is where to repose our love so that everyone can become happy. At the present moment the human society teaches one to love his country or family or his personal self, but there is no information where to repose the loving propensity so that everyone can become happy. That missing point is Kṛṣṇa, and The Nectar of Devotion teaches us how to stimulate our original love for Kṛṣṇa and how to be situated in that position where we can enjoy our blissful life.
In the primary stage a child loves his parents, then his brothers and sisters, and as he daily grows up he begins to love his family, society, community, country, nation, or even the whole human society. But the loving propensity is not satisfied even by loving all human society; that loving propensity remains imperfectly fulfilled until we know who is the supreme beloved. Our love can be fully satisfied only when it is reposed in Kṛṣṇa. This theme is the sum and substance of The Nectar of Devotion, which teaches us how to love Kṛṣṇa in five different transcendental mellows.