Bilvamaṅgala Thākur, in his book Kṛṣṇa-karṇāmṛta, says, "Let the impersonalists be engaged in the process of transcendental realization by worshiping the impersonal Brahman. Although I was also initiated into that path of Brahman realization, I have now become misled by a naughty boy—one who is very cunning, who is very much attached to the gopīs and who has made me His maidservant. So I have now forgotten the process of Brahman realization."
Bilvamaṅgala Thākur was first spiritually initiated for impersonal realization of the absolute truth, but later on, by his association with Kṛṣṇa in Vṛndāvana, he became an experienced devotee. The same thing happened to Śukadeva Gosvāmī, who also reformed himself by the grace of the Lord and took to the path of devotional service, giving up the way of impersonal realization.
Śukadeva Gosvāmī and Bilvamaṅgala Thākur's giving up of the impersonal conception of the absolute truth and taking to devotional service are the best examples of devotees being situated in the neutral state. According to some authorities, this condition cannot be accepted as one of the transcendental humors, or rasas, but Śrīla Rūpa Gosvāmī says that even if one does not accept it as a transcendental humor, one must still accept it as the beginning position of devotional service. However, if one is not further raised to the platform of actual service to the Lord, he is not considered to be on the platform of transcendental mellow. In this connection, in the Eleventh Canto of Śrīmad-Bhāgavatam, Lord Kṛṣṇa personally instructs Uddhava like this: "The state of being established in My personal form is called śānta-rasa, and without being situated in this position, no one can advance to actual pure devotional service." In other words, no one can be situated in the personal feature of the Supreme Personality of Godhead without being situated at least in śānta-rasa.