Generally people think that one should act very piously in order to be relieved from misery, but this is not a fact. Even though one engages in pious activity and speculation, he is nonetheless defeated. His only aim should be emancipation from the clutches of māyā and all material activities. Speculative knowledge and pious activity do not solve the problems of material life. One should be inquisitive to understand his spiritual position. As stated in Bhagavad-gītā (4.37):
yathaidhāṁsi samiddho 'gnir
bhasmasāt kurute 'rjuna
jñānāgniḥ sarva-karmāṇi
bhasmasāt kurute tathā
"As a blazing fire turns firewood to ashes, O Arjuna, so does the fire of knowledge burn to ashes all reactions to material activities."
(Srimad Bhagavatam-----5:5:5-----purport).

In the lower stage of human life the same misconception is also prominent in the shape of "It is my body," "It is my house," "It is my family," "It is my caste," "It is my nation," "It is my country," and so on. And in the higher stage of speculative knowledge, the same misconception of "mine" is transformed into "I am," or "It is all I am," etc. There are many classes of men comprehending the same misconception of "I" and "mine', in different colors. But the real significance of "I" can be realized only when one is situated in the consciousness of "I am the eternal servitor of the Lord." This is pure consciousness, and the whole Vedic literatures teach us this conception of life.
(Srimad Bhagavatam-----2:9:3-----purport).

For a conditioned soul, therefore, it is very important to hear from the mouth of a pure devotee, who is fully surrendered to the lotus feet of the Lord without any material desire, speculative knowledge or contamination of the modes of material nature. Every one of us is kuyogī because we have engaged in the service of this material world, forgetting our eternal relationship with the Lord as His eternal loving servants. It is our duty to rise from the kuyoga platform to become suyogīs, perfect mystics. The process of hearing from a pure devotee is recommended in all Vedic scriptures, especially by Lord Caitanya Mahāprabhu. One may stay in his position of life—it does not matter what it is—but if one hears from the mouth of a pure devotee, he gradually comes to the understanding of his relationship with the Lord and thus engages in His loving service, and his life becomes completely perfect.
(Srimad Bhagavatam-----4:20:25-----purport).

"O King, no one can know the plan of the Lord (Śrī Kṛṣṇa). Even though great philosophers inquire exhaustively, they are bewildered." No one, therefore, can understand God by speculative knowledge. Indeed, by speculation one will be bewildered (muhyanti). This is also confirmed by the Lord Himself in Bhagavad-gītā (7.3):
manuṣyāṇāṁ sahasreṣu
kaścid yatati siddhaye
yatatām api siddhānāṁ
kaścin māṁ vetti tattvataḥ
Among many thousands of men, one may endeavor for perfection, and even among the siddhas, those who have already become perfect, only one who adopts the process of bhakti, devotional service, can understand Kṛṣṇa.
(Srimad Bhagavatam-----6:3:14-15-----purport).

The conditioned soul cannot understand the Supreme Personality of Godhead by speculative knowledge or by imagination. One must therefore know the Supreme Personality of Godhead by the grace of the Supreme Personality of Godhead. He reveals Himself, but He cannot be understood by speculation. As stated in Śrīmad-Bhāgavatam (10.14.29):
athāpi te deva padāmbuja-dvaya-
prasāda-leśānugṛhīta eva hi
jānāti tattvaṁ bhagavan-mahimno
na cānya eko 'pi ciraṁ vicinvan
"My Lord, if one is favored by even a slight trace of the mercy of Your lotus feet, he can understand the greatness of Your personality. But those who speculate to understand the Supreme Personality of Godhead are unable to know You, even though they continue to study the Vedas for many years."
(Srimad Bhagavatam-----6:4:34-----purport).

There is no doubt about it. Śrī Kṛṣṇa's form, Śrī Kṛṣṇa's flute, Kṛṣṇa's color—everything is reality. Here it is said that this vijñānam is always defeating all kinds of speculative knowledge. "Therefore," the demigods prayed, "without Your appearing as Kṛṣṇa, as You are, neither ajñāna-bhidā (the nescience of speculative knowledge) nor vijñānam would be realized. Ajñāna-bhidāpamārjanam—by Your appearance the speculative knowledge of ignorance will be vanquished, and the real, experienced knowledge of authorities like Lord Brahmā will be established. Men influenced by the three modes of material nature imagine their own God according to the modes of material nature. In this way God is presented in various ways, but Your appearance will establish what the real form of God is."
(Srimad Bhagavatam-----10:2:35-----purport).

If the heart is filled with straw, grains of sand, weeds or dust (in other words, anyābhilāṣa-pūrṇa), one cannot enthrone the Supreme Personality of Godhead there. The heart must be cleansed of all material motives brought about through fruitive work, speculative knowledge, the mystic yoga system and so many other forms of so-called meditation. The heart must be cleansed without ulterior motive. As Śrīla Rūpa Gosvāmī says, anyābhilāṣitā-śūnyaṁ jñāna-karmādy-anāvṛtam (Bhakti-rasāmṛta-sindhu 1.1.11). In other words, there should not be any external motive. One should not attempt material upliftment, understanding the Supreme by speculative knowledge, fruitive activity, severe austerity and penance, and so on. All these activities are against the natural growth of spontaneous love of Godhead. As soon as these are present within the heart, the heart should be understood to be unclean and therefore unfit to serve as Kṛṣṇa's sitting place.
(Sri Caitanya Caritamrta-----2:12:135-----purport).

Sometimes a neophyte devotee or ordinary person thinks highly of speculative knowledge, austerity, penances and renunciation, thinking them the only path for advancement in devotional service. Actually this is not a fact. The path of knowledge, mystic yoga and renunciation has nothing to do with the pure soul. When one is temporarily in the material world, such processes may help a little, but they are not necessary for a pure devotee of Kṛṣṇa. In the material world, such activities end in material enjoyment or merging into the effulgence of the Supreme. They have nothing to do with the eternal loving service of the Lord. If one abandons speculative knowledge and simply engages in devotional service, he has attained his perfection. The devotee has no need for speculative knowledge, pious activity or mystic yoga. All these are automatically present when one renders the Lord transcendental loving service.
(Sri Caitanya Caritamrta-----2:22:145-----purport).

Many, many philosophers, scholars, and so-called invincible heroes have tried to make the Supreme Lord impotent, formless, and impersonal, but in the end they always suffered terribly.
Thus in the Śrīmad-Bhāgavatam (10.14.4) we find this statement by Lord Brahmā:
śreyaḥ-sṛtiṁ bhaktim udasya te vibho
kliśyanti ye kevala-bodha-labdhaye
teṣām asau kleśala eva śiṣyate
nānyad yathā sthūla-tuṣāvaghātinām
"My dear Lord, devotional service unto You is the best path for self-realization. If someone gives up that path and engages in the cultivation of speculative knowledge, he will simply undergo a troublesome process and will not achieve his desired result. As a person who beats an empty husk of wheat cannot get grain, one who simply speculates cannot achieve self-realization. His only gain is trouble."
(Renunciation through Wisdom).

As the only way to see the sun is by the help of sunlight, so the only way to see the Supreme Personality, Lord Kṛṣṇa, is by the illumination of sunlike Kṛṣṇa Himself. Only by surrendering to His lotus feet and rendering Him loving devotional service can one approach Him. Neither fruitive activity through physical strain nor speculative knowledge through mental gymnastics can help one attain the highest perfection of God consciousness. Only through bhakti, or devotion, can the Supreme Lord be achieved. Speculative knowledge and mystic yoga can at best accord one a partial realization of the Absolute Truth—namely, realization of Brahman and Paramātmā (the Supersoul), respectively. It is through the singular means of bhakti that one can perceive face to face the Supreme Personality of Godhead, Kṛṣṇa, the embodiment of eternity, knowledge, and bliss.
(Renunciation through Wisdom).