1. Srimad bhagavata canto 1 chapter 2 text 11-12
The Absolute truth and
the process of learning

2. Text 11
vadanti tat tattva-vidas tattvaṁ yaj jñānam advayam brahmeti paramātmeti bhagavān iti śabdyate
Learned transcendentalists who know the Absolute Truth call this nondual substance Brahman, Paramātmā or Bhagavān.

3. Brahman, paramatma & Bhagavan
The Absolute Truth is both subject and object, and there is no qualitative difference there. Therefore, Brahman, Paramātmā and Bhagavān are qualitatively one and the same.
The same substance is realized as impersonal Brahman by the students of the Upaniṣads, as localized Paramātmā by the Hiraṇyagarbhas or the yogīs, and as Bhagavān by the devotees.
Bhagavān, or the Personality of Godhead, is the last word of the Absolute Truth.
Paramātmā is the partial representation of the Personality of Godhead.
Impersonal Brahman is the glowing effulgence of the Personality of Godhead

4. Relative and the absolute world
The Supreme Truth is self-sufficient, cognizant and free from the illusion of relativity.
In the relative world the knower is different from the known, but in the Absolute Truth both the knower and the known are one and the same thing.
There are three kinds of energies of the supreme energetic.
There is no difference between the energy and energetic, but there is a difference of quality of energies.
The absolute realm and the living entities are of the same superior energy, but the material world is inferior energy.
The living being in contact with the inferior energy is illusioned, thinking he belongs to the inferior energy.
In the Absolute there is no such sense of difference between the knower and the known, and therefore everything there is absolute.

5. Text 12
tac chraddadhānā munayo jñāna-vairāgya-yuktayā paśyanty ātmani cātmānaṁ bhaktyā śruta-gṛhītayā The seriously inquisitive student or sage, well equipped with knowledge and detachment, realizes that Absolute Truth by rendering devotional service in terms of what he has heard from the Vedānta-śruti.

6. Three kinds of devotees
The Absolute Truth is realized in full by the process of devotional service to the Lord, Vāsudeva, or the Personality of Godhead, who is the full-fledged Absolute Truth.
Brahman or Paramātmā realization of the Absolute Truth is but a partial realization.
There are four different types of human beings—the karmīs, the jñānīs, the yogīs and the devotees. The karmīs are materialistic, whereas the other three are transcendental.
The first-class transcendentalists are the devotees who have realized the Supreme Person.
The second-class transcendentalists are those who have partially realized the plenary portion of the absolute person.
And the third-class transcendentalists are those who have barely realized the spiritual focus of the absolute person.

7. The Supreme Person is realized by devotional service, which is backed by full knowledge and detachment from material association.
Brahman and Paramātmā realization are imperfect realizations of the Absolute Truth, so the means of realizing Brahman and Paramātmā, i.e., the paths of jñāna and yoga, are also imperfect means of realizing the Absolute Truth.
Devotional service, which is based on the foreground of full knowledge combined with detachment from material association and which is fixed by the aural reception of the Vedānta-śruti, is the only perfect method by which the seriously inquisitive student can realize the Absolute Truth.
Devotional service is not, therefore, meant for the less intelligent class of transcendentalist.
There are three classes of devotees, namely first, second, and third class.

8. Third class or the material devotees - Material devotees are more attached to material benefit than transcendental profit.
In the second-class position, the devotee can see four principles in the devotional line, namely the Personality of Godhead, His devotees, the ignorant and the envious.
The number one Bhāgavata is the established personality of devotee, and the other Bhāgavatam is the message of Godhead.
A third-class devotee, therefore, has to receive the instructions of devotional service from the authoritative sources of Bhāgavata.
Such a personality of devotee is not a professional man who earns his livelihood by the business of Bhāgavatam.
Such a devotee must be a representative of Śukadeva Gosvāmī, like Sūta Gosvāmī, and must preach the cult of devotional service for the all-around benefit of all people.

9. Transcendental matters are not to be received from the professional man, who spoils them as the serpent spoils milk simply by the touch of his tongue.
A sincere devotee must, therefore, be prepared to hear the Vedic literature like the Upaniṣads, Vedānta and other literatures left by the previous authorities or Gosvāmīs, for the benefit of his progress.
Unless, therefore, devotional service is established on the principles of śruti, smṛti, purāṇa or pañcarātra authorities, the make-show of devotional service should at once be rejected.
An unauthorized devotee should never be recognized as a pure devotee. By assimilation of such messages from the Vedic literatures, one can see the all-pervading localized aspect of the Personality of Godhead within his own self constantly.
This is called samādhi.