From Chapter I of Para-Bhakti or Supreme Devotion of Volume 3 of Complete Works of Swami Vivekananda.
We have now finished the consideration of what may be called the preparatory Bhakti, and are entering on the study of the Parâ-Bhakti or supreme devotion. We have to speak of a preparation to the practice of this Para-Bhakti. All such preparations are intended only for the purification of the soul. The repetition of names, the rituals, the forms, and the symbols, all these various things are for the purification of the soul. The greatest purifier among all such things, a purifier without which no one can enter the regions of this higher devotion (Para-Bhakti), is renunciation. This frightens many; yet, without it, there cannot be any spiritual growth. In all our Yogas this renunciation is necessary. This is the stepping-stone and the real centre and the real heart of all spiritual culture — renunciation. This is religion — renunciation.
When the human soul draws back from the things of the world and tries to go into deeper things; when man, the spirit which has here somehow become concretised and materialised, understands that he is thereby going to be destroyed and to be reduced almost into mere matter, and turns his face away from matter — then begins renunciation, then begins real spiritual growth. The Karma-Yogi’s renunciation is in the shape of giving up all the fruits of his action; he is not attached to the results of his labour; he does not care for any reward here or hereafter. The Râja-Yogi knows that the whole of nature is intended for the soul to acquire experience, and that the result of all the experiences of the soul is for it to become aware of its eternal separateness from nature. The human soul has to understand and realise that it has been spirit, and not matter, through eternity, and that this conjunction of it with matter is and can be only for a time. The Raja-Yogi learns the lesson of renunciation through his own experience of nature. The Jnâna-Yogi has the harshest of all renunciations to go through, as he has to realise from the very first that the whole of this solid-looking nature is all an illusion. He has to understand that all that is any kind of manifestation of power in nature belongs to the soul, and not to nature. He has to know from the very start that all knowledge and all experience are in the soul and not in nature; so he has at once and by the sheer force of rational conviction to tear himself away from all bondage to nature. He lets nature and all that belongs to her go, he lets them vanish and tries to stand alone!
Of all renunciations, the most natural, so to say, is that of the Bhakti-Yogi. Here there is no violence, nothing to give up, nothing to tear off, as it were, from ourselves, nothing from which we have violently to separate ourselves. The Bhakta’s renunciation is easy, smooth flowing, and as natural as the things around us. We see the manifestation of this sort of renunciation, although more or less in the form of caricatures, every day around us. A man begins to love a woman; after a while he loves another, and the first woman he lets go. She drops put of his mind smoothly, gently, without his feeling the want of her at all. A woman loves a man; she then begins to love another man, and the first one drops off from her mind quite naturally. A man loves his own city, then he begins to love his country, and the intense love for his little city drops off smoothly, naturally. Again, a man learns to love the whole world; his love for his country, his intense, fanatical patriotism drops off without hurting him, without any manifestation of violence. An uncultured man loves the pleasures of the senses intensely; as he becomes cultured, he begins to love intellectual pleasures, and his sense-enjoyments become less and less. No man can enjoy a meal with the same gusto or pleasure as a dog or a wolf, but those pleasures which a man gets from intellectual experiences and achievements, the dog can never enjoy. At first, pleasure is in association with the lowest senses; but as soon as an animal reaches a higher plane of existence, the lower kind of pleasures becomes less intense. In human society, the nearer the man is to the animal, the stronger is his pleasure in the senses; and the higher and the more cultured the man is, the greater is his pleasure in intellectual and such other finer pursuits. So when a man gets even higher than the plane of the intellect, higher than that of mere thought, when he gets to the plane of spirituality and of divine inspiration, he finds there a state of bliss, compared with which all the pleasures of the senses, or even of the intellect, are as nothing. When the moon shines brightly, all the stars become dim; and when the sun shines, the moon herself becomes dim. The renunciation necessary for the attainment of Bhakti is not obtained by killing anything, but just comes in as naturally as in the presence of an increasingly stronger light, the less intense ones become dimmer and dimmer until they vanish away completely. So this love of the pleasures of the senses and of the intellect is all made dim and thrown aside and cast into the shade by the love of God Himself.
That love of God grows and assumes a form which is called Para-Bhakti or supreme devotion. Forms vanish, rituals fly away, books are superseded; images, temples, churches, religions and sects, countries and nationalities — all these little limitations and bondages fall off by their own nature from him who knows this love of God. Nothing remains to bind him or fetter his freedom. A ship, all of a sudden, comes near a magnetic rock, and its iron bolts and bars are all attracted and drawn out, and the planks get loosened and freely float on the water. Divine grace thus loosens the binding bolts and bars of the soul, and it becomes free. So in this renunciation auxiliary to devotion, there is no harshness, no dryness no struggle, nor repression nor suppression. The Bhakta has not to suppress any single one of his emotions, he only strives to intensify them and direct them to God.