In Śrīmad-Bhāgavatam (10.14.4) it is clearly said that one who engages in spiritual life to understand things as they are but who lacks all intention of engaging in Kṛṣṇa consciousness simply achieves trouble for his undertaking. There is no substance to his life. Every living entity is part and parcel of the Supreme Lord, and therefore it is the duty of every living entity to serve that supreme whole. Without such service, the living entity falls into material contamination.
Lord Caitanya concluded His teachings to Sanātana Gosvāmī by pointing out that the six kinds of ātmārāmas, or transcendentalists, engage in some kind of devotional service to Kṛṣṇa. In other words, at some time or another all the transcendentalists ultimately come to understand the necessity of rendering devotional service to Kṛṣṇa and become fully Kṛṣṇa conscious. Even if one is very learned or extravagant, he can still engage in the devotional service of the Lord.
The six kinds of transcendentalists are the neophyte transcendentalist, the absorbed transcendentalist, one who is situated in transcendence, one who desires liberation, one who is actually liberated, and one who is engaged in activities in his constitutional position. All of these are ātmārāmas. When a person becomes an ātmārāma, or a great thinker in Kṛṣṇa consciousness, he fully engages in devotional service. According to the grammatical rules, there are many kinds of ātmārāmas, but one sense of the word is sufficient to represent the others. In the collective sense, all the ātmārāmas are inclined to worship the Supreme Lord, Kṛṣṇa.
The mystic who worships the Supersoul within himself is also an ātmārāma. The ātmārāma yogīs are of two kinds: sagarbha and nigarbha. It is stated in Śrīmad-Bhāgavatam (2.2.8): "Some yogīs meditate within their heart on the localized Viṣṇu, who is four-handed and who holds four symbols: conch, disc, mace and lotus." The yogī who thinks of the four-handed Viṣṇu becomes absorbed in devotional ecstasy and shows the symptoms of that state. Sometimes he cries, and sometimes he feels separation from the Lord. In this way he merges in transcendental bliss, resulting in his becoming entrapped like a fish.