One who can fix his mind on Kṛṣṇa without deviation attains śānta-rasa, the steadfast position in Kṛṣṇa consciousness. One in śānta-rasa exhibits two main qualities: unflinching faith in Kṛṣṇa, and the cessation of all material desires. These specific characteristics of śānta-rasa—unflinching faith in Kṛṣṇa and cessation of all desires not connected with Kṛṣṇa—are common to all other rasas as well, just as sound is present not only in sky, where it is produced, but also in all the other elements—air, fire, water and earth. So these two characteristics of śānta-rasa are also present in dāsya-rasa (servitorship), sakhya-rasa (fraternity), vātsalya-rasa (parental affection) and madhura-rasa (conjugal love).
When we speak of desires not connected with Kṛṣṇa, or "non-Kṛṣṇa," this does not mean that anything exists without Kṛṣṇa. Actually there cannot be anything non-Kṛṣṇa because everything is a product of the energy of Kṛṣṇa. Since Kṛṣṇa and His energies are identical, everything is Kṛṣṇa indirectly. For example, consciousness is common to every living entity, but when consciousness is centered solely on Kṛṣṇa (Kṛṣṇa consciousness) it is pure, and when consciousness is centered on something other than Kṛṣṇa, or when it is directed to sense gratification, it may be called non-Kṛṣṇa consciousness. Thus it is in the polluted state that the conception of non-Kṛṣṇa comes. In the pure state, however, there is nothing but Kṛṣṇa consciousness.
Active interest in Kṛṣṇa—the understanding that Kṛṣṇa is mine and that I am Kṛṣṇa's and that my business is therefore to satisfy the senses of Kṛṣṇa—is typical of a higher stage than the neutrality of śānta-rasa. Simply by understanding the greatness of Kṛṣṇa, one achieves the status of śānta-rasa, in which the worshipable object may be the impersonal Brahman or Paramātmā. Worship of the impersonal Brahman and the Paramātmā is conducted by those engaged in empiric philosophical speculation and mystic yoga. But when one develops even further in Kṛṣṇa consciousness, or spiritual understanding, he can appreciate that the Paramātmā, the Supersoul, is his eternal worshipable object and master, and he surrenders unto Him. Bahūnāṁ janmanām ante jñānavān māṁ prapadyate (BG 7.19): "After many, many births of worshiping Brahman and Paramātmā, when one surrenders unto Vāsudeva as the supreme master and accepts himself as the eternal servant of Vāsudeva, he becomes a great transcendentally realized soul." At that time, due to his intimate relationship with the Supreme Absolute Truth, the devotee begins to render some sort of transcendental loving service to the Supreme Personality of Godhead. Thus the neutral relationship known as śānta-rasa is transformed into dāsya-rasa, servitorship.