The Bhagavad-gītā is the essence of all Vedic knowledge. It is the first book of spiritual values, as the Upaniṣads are. The Vedānta philosophy is the subject matter for study by the spiritual graduates. Only the post-graduate spiritual student can enter into the spiritual or devotional service of the Lord. It is a great science, and the great professor is the Lord Himself in the form of Lord Śrī Caitanya Mahāprabhu.
(Srimad Bhagavatam------1:4:25------purport).

Such a scholar as Vyāsadeva has completed many expansions of the Vedic literatures, ending with the Vedānta philosophy, but none of them have been written directly glorifying the Personality of Godhead. Dry philosophical speculations even on the transcendental subject of the Absolute have very little attraction without directly dealing with the glorification of the Lord. The Personality of Godhead is the last word in transcendental realization.
(Srimad Bhagavatam------1:5:8------purport).

Unless one has become a sufficiently learned philosopher by hearing the Vedānta philosophy from a bona fide spiritual master, one cannot be a learned philosopher devotee. One must be very faithful, learned and renounced, otherwise one cannot be a pure devotee.
(Srimad Bhagavatam------1:13:40------purport).

As stated in the Bhagavad-gītā (15.15), the Lord is Himself the father of the Vedānta knowledge, and it is He only who knows the factual purport of the Vedānta philosophy. So there is no greater truth than the principles of religion mentioned in the Vedas.
(Srimad Bhagavatam------2:4:23------purport).

Generally, a person who strictly follows the Vedic principles is called veda-vādi. There are also so-called Vedāntists who advertise themselves as followers ofVedānta philosophy but who misinterpret Vedānta. The expression veda-vāda-ratāḥ is also found in the Bhagavad-gītā, referring to persons who are attached to the Vedas without understanding the purport of the Vedas.
(Srimad Bhagavatam------4:12:41------purport).

The Vedas deal mostly with fruitive activities to gradually elevate the general public from the field of sense gratification to a position on the transcendental plane. Arjuna, as a student and friend of Lord Kṛṣṇa, is advised to raise himself to the transcendental position of Vedānta philosophy where, in the beginning, there is brahma-jijñāsā, or questions on the supreme transcendence.
(Bhagavad-Gita------2:45-------purport).

When Lord Caitanya was asked by a great Vedic scholar, Prakāśānanda Sarasvatī, why He, the Lord, was chanting the holy name of the Lord like a sentimentalist instead of studying Vedānta philosophy, the Lord replied that His spiritual master had found Him to be a great fool and thus asked Him to chant the holy name of Lord Kṛṣṇa. He did so, and became ecstatic like a madman.
(Bhagavad-Gita------2:46-------purport).

In this Age of Kali, most of the population is foolish and not adequately educated to understand Vedānta philosophy; the best purpose of Vedānta philosophy is served by inoffensively chanting the holy name of the Lord. Vedānta is the last word in Vedic wisdom, and the author and knower of the Vedānta philosophy is Lord Kṛṣṇa; and the highest Vedāntist is the great soul who takes pleasure in chanting the holy name of the Lord.
(Bhagavad-Gita------2:46-------purport).

Śrī Kṛṣṇa is the potent factor, and Śrīmatī Rādhārāṇī is the internal potency. According to Vedānta philosophy, there is no difference between the potent and the potency; they are identical. We cannot differentiate between one and the other, any more than we can separate fire from heat.
(Sri Caitanya Caritamrta------1:4:56------purport).

The first conclusion is accepted by the Vedānta philosophers, and the second is supported by the atheistic philosophical system of the Sāṅkhya smṛti, which directly opposes the Vedāntic philosophical conclusion. Material scientists cannot see any cognizant spiritual substance that might be the cause of the creation. Such atheistic Sāṅkhya philosophers think that the symptoms of knowledge and living force visible in the innumerable living creatures are caused by the three qualities of the cosmic manifestation. Therefore the Sāṅkhyites are against the conclusion of Vedānta regarding the original cause of creation.
(Sri Caitanya Caritamrta------1:6:14-15------purport).

Lord Kṛṣṇa is the actual compiler of Vedānta, and whatever He speaks is Vedānta philosophy. Although they are lacking the knowledge of Vedānta presented by the Supreme Personality of Godhead in the transcendental form of Śrīmad-Bhāgavatam, the Māyāvādīs are very proud of their study. Foreseeing the bad effects of their presenting Vedānta philosophy in a perverted way, Śrīla Vyāsadeva compiled Śrīmad-Bhāgavatam as a commentary on the Vedānta-sūtra.
(Sri Caitanya Caritamrta------1:7:41------purport).

Śrīmad-Bhāgavatam is bhāṣyo ’yaṁ brahma-sūtrāṇām; in other words, all the Vedānta philosophy in the aphorisms of the Brahma-sūtra is thoroughly described in the pages of Śrīmad-Bhāgavatam. Thus the factual propounder of Vedānta philosophy is a Kṛṣṇa conscious person who always engages in reading and understanding the Bhagavad-gītā and Śrīmad-Bhāgavatam and teaching the purport of these books to the entire world.
(Sri Caitanya Caritamrta------1:7:41------purport).

One who is very much attracted to the study of Vedānta philosophy must take lessons from Śrī Caitanya Mahāprabhu. In this age, no one is actually competent to study Vedānta, and therefore it is better that one chant the holy name of the Lord, which is the essence of all Vedic knowledge, as Kṛṣṇa Himself confirms in the Bhagavad-gītā (15.15):
vedaiś ca sarvair aham eva vedyo
vedānta-kṛd veda-vid eva cāham
"By all the Vedas, I am to be known. Indeed, I am the compiler of Vedānta, and I am the knower of the Vedas."
(Sri Caitanya Caritamrta------1:7:72------purport).

One who imperfectly knows Kṛṣṇa consciousness cannot know Vedānta philosophy. A showy display of Vedānta study without Kṛṣṇa consciousness is a feature of the external energy, māyā, and as long as one is attracted by the inebrieties of this ever-changing material energy, he deviates from devotion to the Supreme Personality of Godhead.
(Sri Caitanya Caritamrta------1:7:72------purport).

An actual follower of Vedānta philosophy is a devotee of Lord Viṣṇu, who is the greatest of the great and the maintainer of the entire universe. Unless one surpasses the field of activities in service to the limited, one cannot reach the unlimited. Knowledge of the unlimited is actual brahma-jñāna, or knowledge of the Supreme
(Sri Caitanya Caritamrta------1:7:72------purport).

One who is unfit to chant the holy name of Kṛṣṇa but thinks that the holy name is different from Kṛṣṇa and thus takes shelter of Vedānta study in order to understand Him must be considered a number one fool, as confirmed by Caitanya Mahāprabhu by His personal behavior, and philosophical speculators who want to make Vedānta philosophy an academic career are also considered to be within the material energy.
(Sri Caitanya Caritamrta------1:7:72------purport).

A person who always chants the holy name of the Lord, however, is already beyond the ocean of nescience, and thus even a person born in a low family who engages in chanting the holy name of the Lord is considered to be beyond the study of Vedānta philosophy.
(Sri Caitanya Caritamrta------1:7:72------purport).

A devotee must know the importance of simultaneously understanding Vedānta philosophy and chanting the holy names. If by studying Vedānta one becomes an impersonalist, he has not been able to understand Vedānta. This is confirmed in the Bhagavad-gītā (15.15). Vedānta means "the end of knowledge." The ultimate end of knowledge is knowledge of Kṛṣṇa, who is identical with His holy name.
(Sri Caitanya Caritamrta------1:7:72------purport).

Bhakti develops in pursuance of Vedānta philosophy. This is stated in Śrīmad-Bhāgavatam (1.2.12):
tac chraddadhānā munayo jñāna-vairāgya-yuktayā
paśyanty ātmani cātmānaṁ bhaktyā śruta-gṛhītayā
The words bhaktyā śruta-gṛhītayā in this verse are very important, for they indicate that bhakti must be based upon the philosophy of the Upaniṣads and Vedānta-sūtra.
(Sri Caitanya Caritamrta------1:7:102------purport).

Actually Vedānta philosophy is meant for the devotees because in the Bhagavad-gītā (15.15) Lord Kṛṣṇa says, vedānta-kṛd veda-vid eva cāham: "I am the compiler of Vedānta, and I am the knower of the Vedas." Vyāsadeva is an incarnation of Kṛṣṇa, and consequently Kṛṣṇa is the compiler of Vedānta philosophy. Therefore Kṛṣṇa clearly knows the purport of Vedānta philosophy.
(Sri Caitanya Caritamrta------2:17:96------purport).

As long as one is within the limited jurisdiction of fruitive activities or is involved in mental speculation, he may perhaps be eligible to study or teach the theoretical knowledge of Vedānta-sūtra, but he cannot understand the supreme, eternal, transcendental (completely liberated) vibration of Hare Kṛṣṇa, Hare Kṛṣṇa, Kṛṣṇa Kṛṣṇa, Hare Hare/ Hare Rāma, Hare Rāma, Rāma Rāma, Hare Hare. One who has achieved perfection in chanting the transcendental Hare Kṛṣṇa vibration does not have to separately learn thephilosophy of Vedānta-sūtra.
(Teachings of Lord Caitanya).