Hearing authorized descriptions of the Supreme Lord from the Vedic literature should produce ecstasy. This is the symptom of genuine Kṛṣṇa consciousness. Kṛṣṇa consciousness is not a subject to be studied as mythology or as comparative religion, and certainly not as a means of reaching impersonal meditation. Merely to be neutral concerning God or to theoretically acknowledge, "Yes, I believe God exists," is not enough. Hearing about Lord Kṛṣṇa should initially produce a regret within the conditioned soul that he has been so long separated from his master, protector, and best friend. Ultimately, with tears of love, he should feel pure affection with the revival of his natural and all-fulfilling relationship with the Lord.
The process of bhakti has three stages: sambandha, abhidheya, and prayojana. In the first stage one hears from authorized sources and awakens to the understanding of the Supreme Personality of Godhead, oneself, the creation, and the relationship among all these. One then realizes the supreme value of bhakti-yoga, devotional service unto the all-attractive Lord. In the second stage, called abhidheya, one engages in the practical activities of devotional service. This culminates in the final stage, prayojana, in which one achieves pure love of God, the goal of life.
In a Śrīmad-Bhāgavatam verse similar to this one by King Kulaśekhara, Śukadeva Gosvāmī describes the unfortunate position of one who doesn't awaken to the message of Godhead:
tad aśma-sāraṁ hṛdayaṁ batedaṁ
yad gṛhyamāṇair hari-nāma-dheyaiḥ
na vikriyetātha yadā vikāro
netre jalaṁ gātra-ruheṣu harṣaḥ
"Certainly that heart is steel-framed which, in spite of one's chanting the holy name of the Lord with concentration, does not change and feel ecstasy, at which time tears fill the eyes and the hairs stand on end" (SB 2.3.24).
The ācāryas warn us that pretenders imitate these symptoms, complete with tears and bristling hair. Therefore the most reliable symptoms of advancement are detachment from material pleasures and steady, sincere service to the Lord under the guidance of the spiritual master.
This does not negate, however, the importance of ecstasy. In His Śikṣāṣṭaka (2) Lord Caitanya, taking the role of a conditioned soul, laments that although He chants the holy name, He fails to achieve ecstasy because He is so unfortunate that He cannot stop committing offenses. Thus if we want to progress toward love of Godhead, we must study and carefully avoid the ten offenses to the holy name. (See The Nectar of Devotion)
One who is fortunate enough to get the association of a pure devotee of the Lord can rectify all these bad habits. Otherwise, one will remain steel-hearted and unfit to advance in devotional service. Śrīla Prabhupāda writes, "A complete progressive march on the return path home, back to Godhead, will depend on the instruction of the revealed scriptures directed by realized devotees." By serving the pure devotee one will automatically experience the progressive and ecstatic stages of bhakti, without disappointment or imitation.