Kṛṣṇa says, God directly says, that "I am the origin of everything." Ahaṁ sarvasya prabhavo mattaḥ sarvaṁ pravartate: "Everything emanates from Me." Iti matvā, "When one understands this," budha, "a learned person," bhajante māṁ dṛḍha-vratāḥ, "he engages himself fully in Kṛṣṇa consciousness." So Kṛṣṇa is the origin of everything, but it takes little time, according to the position of the man, to understand it. This is a fact, that Kṛṣṇa is the origin of everything. But the intelligent man can understand it very easily; therefore he takes to Kṛṣṇa consciousness. And those who are not intelligent, he tries to understand whether Kṛṣṇa is the origin of everything; therefore it takes some time. Therefore persons who are making research, what is the origin of everything, they are also learned scholars - but because they are doing in their own way, therefore it takes many, many births to understand that Kṛṣṇa is the origin of everything.
So in this way of material research, one will come to the conclusion, if he is really a research scholar that vāsudevaḥ sarvam iti (BG 7.19). But those who are more purified, instead of making research, he immediately accepts that Kṛṣṇa is the origin of everything. So just to understand Kṛṣṇa, Kṛṣṇa is explaining Himself in the Bhagavad-gītā. So if one is fortunate, if one is intelligent, if he accepts Kṛṣṇa's version—Kṛṣṇa says at last, sarva-dharmān parityajya mām ekaṁ śaraṇaṁ vraja (BG 18.66)—he accepts it. So one who has accepted Kṛṣṇa as the supreme source, Absolute Truth, for them, this Śrīmad-Bhāgavatam is there.