The essence of Bhakti Yoga is love. Human love attempts to develop an intense bond between different individuals as an attempt to bridge the gap of separation. Of all human bonds, the bond of love is the most intense. There are different forms of love, the love of parent for child, the love of friend for friend, but the ultimate experience of human love is that of lover and beloved. Bhakti Yoga turns each form of love towards the divine, including that of the lover and the beloved, and this is the inner secret of the Vaishnava in the ecstatic bliss of the Krishna Lila.
Sri Aurobindo observes: “Passing beyond desire of possession which means a difference, it is a seeking for oneness, and it is here that the idea of oneness, of two souls merging into each other and becoming one finds the acme of its longing and the utterness of its satisfaction. Love, too, is a yearning for beauty, and it is here that the yearning is eternally satisfied in the vision and the touch and the joy of the All-beautiful. Love is a child and a seeker of Delight, and it is here that it finds the highest possible ecstasy both of the heart-consciousness and of every fibre of the being. Moreover, this relation is that which as between human being and human being demands the most and, even while reaching the greatest intensities, is still the least satisfied, because only in the Divine can it find its real and its utter satisfaction. Therefore it is here most that the turning of human emotion Godwards finds its full meaning and discovers all the truth of which love is the human symbol, all its essential instincts divinised, raised, satisfied in the bliss from which our life was born and towards which by oneness it returns in the Ananda of the divine existence where love is absolute, eternal and unalloyed.”
Sri Aurobindo, The Synthesis of Yoga, Part Three: The Yoga of Divine Love, Chapter 3, The Godward Emotions, pg. 545