Whatever exists—manifest or unmanifest, material or spiritual—has one primary source: the Supreme Lord, Kṛṣṇa. He is the primeval, supreme controller, the cause of all causes, the Lord of all lords. As the Supersoul within the heart, He inspires all the activities of a transcendentally situated devotee. Those who possess true knowledge of the Absolute can render service to Lord Kṛṣṇa in the mood of a servitor, a friend, and so on. Their hearts are always absorbed in thoughts of Lord Kṛṣṇa, and they yearn to perceive and relish His eternal, transcendental pastimes.
By the grace of the Supreme Lord, these unalloyed devotees can unravel the mysteries of His intimate worship. Then, due to their love for the Lord, they find it difficult to maintain their lives without hearing and chanting the glories of the Lord's name, form, qualities, pastimes, associates, and paraphernalia. They seek the association of like-minded devotees, and with them they dive into the ocean of the nectar of devotion. Situated in their spiritual identity, they relish spiritual exchanges and hear, discuss, and remember the all-auspicious topics of Lord Kṛṣṇa's transcendental pastimes, thus practising the ninefold devotional process.
They execute this ninefold devotional service in the stage of sādhana, or practice, and feel deep satisfaction in the perfected, or siddha, stage. They become saturated with the transcendental spiritual mellows of servitorship, friendship, and so on, from which they derive divine ecstasy. Lord Kṛṣṇa grants genuine transcendental understanding, buddhi-yoga, to those devotees who experience spiritual satisfaction and divine bliss through constant devotional service; gradually their specific devotional attitude increases to the point where they can relish pure love of God.
In the stage of bhāva, or spontaneous devotional service in ecstasy, there is a direct transcendental exchange of mellows between Lord Kṛṣṇa and His pure devotee. The Supreme Lord Himself gives His devotee buddhi-yoga, or spiritual intelligence, and the devotee, acting with that intelligence, serves the Lord until he gradually approaches the Lord's supreme abode. Such a devotee can never be affected by ignorance.
The impersonalists and empiric philosophers consider the unalloyed devotees of the Lord sentimental fools, and thus they deride them. This is a big offense. Such offences cause the impersonalists and pseudo-devotees to slowly become demoniac. Having lost good sense and a stable mind, they gradually develop animosity toward the Supreme Lord and find all their life's endeavors reduced to suffering and futility. If one of these deluded demoniac impersonalists comes in contact with a pure devotee and by his mercy regains his lost insight, then he can begin to understand that the pure devotees he offended are exchanging spiritual mellows with Lord Kṛṣṇa and are thus forever free from ignorance and illusion. The impersonalists must understand that the Supreme Lord, acting from within as the Supersoul, removes all ignorance from the devotee's heart.