Actually, all Vedic culture is aiming at understanding Lord Viṣṇu. In the Ṛg Veda one mantra says that any advanced saintly person is always aspiring to be fixed in meditation upon the lotus feet of Viṣṇu.
In Śrīmad-Bhāgavatam it is said that the foolish do not know that Viṣṇu is the ultimate goal of life. According to the conclusion of all authoritative Vedic scriptures, when a person comes to the stage of appreciating Viṣṇu, he is at the beginning of devotional service. If one cultivates devotional service further and further, under proper guidance, other features of devotional service will gradually become manifest. At this stage of śānta-rasa, one can see Lord Viṣṇu, the Supreme Personality of Godhead, the deliverer of even the demons. The Lord is appreciated by such would-be devotees as the eternal transcendental form, the chief of all self-realized souls, the Supersoul and the Supreme Brahman. He is also appreciated as being completely peaceful, completely controlled and pure, merciful to the devotees and untouched by any material condition. This appreciation of Lord Viṣṇu in awe and veneration by the saintly is to be understood as the sign that they are situated in the śānta-rasa, or the neutral stage of devotional service.
This stage of śānta-rasa can be attained by the impersonalists only when they are in association with pure devotees. Otherwise it is not possible. After Brahman realization, when a liberated soul comes in contact with a pure devotee of Lord Kṛṣṇa and submissively accepts the teachings of Lord Kṛṣṇa without misinterpretation, he becomes situated in this neutral stage of devotional service. The best example of saintly persons situated in the śānta-rasa are Sanaka, Sanātana, Sananda and Sanat-kumāra, the Kumāra brothers. These four saintly persons (known as Catuḥ-sana) are sons of Lord Brahmā. After their birth, when they were ordered by their father to become householders and increase human society, they refused the order. They said that they had already decided not to become entangled with family life; they would rather live as saintly brahmacārīs for their own perfection. So these great saints have been living for millions of years now, but still they appear to be just like boys of four or five years. Their complexions are very fair, there is an effulgence in their bodies, and they always travel naked. These four saintly persons almost always remain together.
In one of the prayers of the Kumāra brothers, this declaration is made: "O Lord Mukunda (Kṛṣṇa, the giver of liberation), only so long as one does not happen to see Your eternal form of bliss and knowledge, appearing just like a newly-grown tamāla tree, with a bluish hue—only for so long can the impersonal feature of the Absolute Truth, known as Brahman, be very pleasing to a saintly person."
The qualifications of a saintly person are described in the Bhakti-rasāmṛta-sindhu as follows. A saintly person is one who understands fully that simply by discharging devotional service he can become confident of liberation. He is always situated in the regulative principles of devotional life and at the same time aspires to be liberated from material entanglement.
A saintly person thinks like this: "When shall I be able to live alone in the caves of the mountains? When shall I be dressed simply with undergarments? When shall I be satisfied by eating simply a little fruit and vegetables? When will it be possible for me to think always of the lotus feet of Mukunda, who is the source of the Brahman effulgence? When, in such a spiritual condition of life, shall I fully understand my days and nights to be insignificant moments in eternal time?"
The devotees and self-realized persons who are engaged in preaching the glories of the Lord always maintain an ecstatic love for the Lord within their hearts. Thus they are benefited by the rays of the ecstatic moon, and they are called saintly persons.
The impulse of a saintly person is to be engaged in the study of the Vedas, especially the Upaniṣadic portions, to live always in a place where there is no disturbance from the common people, to think always of the eternal form of Kṛṣṇa, to be ready to consider and understand the Absolute Truth, to be always prominent in exhibiting knowledge, to see the Supreme Lord in His universal form (viśva-rūpa), to associate always with learned devotees and to discuss the conclusion of the Vedas with similarly elevated persons. All of these qualifications of a saintly person serve to raise him to the status of śānta-rasa.
In the Bhakti-rasāmṛta-sindhu it is stated that all those who attended the pious meeting held by Lord Brahmā for the study of Vedic literature like the Upaniṣads became overwhelmed with ecstatic love for Kṛṣṇa, the chief of the Yadu dynasty. Actually, the result of studying the Upaniṣads is to understand the Supreme Personality of Godhead. Negation of material existence is only one of the subjects of the Upaniṣads. The next subject concerns becoming situated in the impersonal realization. And then, after penetrating through the impersonal Brahman, when one comes to the platform of associating with the Supreme Personality of Godhead, one reaches the ultimate goal in studying the Upaniṣads.
Those who are situated on the platform of śānta-rasa get their impetus for advancement in devotional service by smelling the tulasī offered at the lotus feet of the Lord, by hearing the sound of His conchshell, by seeing a sanctified place in some mountain or hill, by observing a forest like the ones in Vṛndāvana, by going to a place of pilgrimage, by visiting the course of the Ganges River, by being victorious over the dictations of bodily demands (i.e., eating, sleeping, mating and defending), by understanding the devastation of eternal time and by constantly associating with devotees engaged in Kṛṣṇa consciousness. All these different items are favorable in elevating saintly persons situated in śānta-rasa to the advanced stage of devotional service.
In the Third Canto, Fifteenth Chapter, verse 43, of the Śrīmad-Bhāgavatam, there is a statement by the four saintly persons known as Catuḥ-sana, headed by Sanaka-kumāra. They went to visit the Lord of Vaikuṇṭhaloka in the spiritual sky, and when they bowed down before the Lord, the aroma of the tulasī, mixed with saffron, entered their nostrils and immediately attracted their minds. Although these four saintly persons were always absorbed in the thought of impersonal Brahman, from association with the Lord and from smelling the tulasī leaves the hairs on their bodies immediately stood up. This shows that even a person who is situated in Brahman realization, if he is put into association with devotees in pure devotional service, will immediately become attracted to the personal feature of the Lord.
There are certain symptoms of great sages who are situated in śānta-rasa devotional service, and these symptoms are exhibited as follows. They concentrate their eyesight on the tip of the nose, and they behave just like an avadhūta. Avadhūta means a highly elevated mystic who does not care for any social, religious or Vedic conventions. Another symptom is that such persons are very careful to step forward when giving speeches. When they speak, they join together the forefinger and thumb. (This is called the jñāna-mudrā position.) They are not against the atheists, nor are they particularly inclined to the devotees. Such persons give stress to liberation and detachment from the materialistic way of life. They are always neutral and have no affection for nor misidentification with anything material. They are always grave, but fully absorbed in thoughts of the Supreme Personality of Godhead. These uncommon features develop in devotees who are situated in śānta-rasa.
Regarding concentration of the eyesight on the tip of the nose, there is a statement in the Bhakti-rasāmṛta-sindhu by a devotee who observed this being performed by a yogī. He remarked, "This great sage is concentrating his eyesight on the tip of his nose, and from this it appears that he has already realized the eternal form of the Lord within himself."
Sometimes a devotee in śānta-rasa yawns, stretches his limbs, instructs on devotional service, offers respectful obeisances unto the form of the Lord, offers nice prayers to the Lord and has a desire to give direct service with his body. These are some of the common symptoms of the devotee who is situated in neutrality. One devotee, after observing the yawning of another devotee, addressed him thus: "My dear mystic, I think that within your heart there is some ecstatic devotional love which is causing you to yawn." It is sometimes found that a devotee in the śānta-rasa falls down on the ground, his hairs stand up on his body, and he trembles all over. In this way, different symptoms of ecstatic trance are exhibited automatically by such devotees.