Higher mathematics cannot be understood by the small schoolboys who are simply trying to understand, "Two plus two equal to four." But "Two plus two equal to four" is equally good to the higher mathematics student. But still, higher mathematics and lower math is different. Therefore it is said, śrutayo vibhinnāḥ: the scriptures are different.
So if you simply try to understand what is God by reading scriptures, you cannot achieve. You must approach a guru. Just like a medical book, it can be available in the market. If you purchase one medical book and study and you become doctor, that is not possible. You must hear the medical book from a medical man in the college, medical college. Then you will be qualified. And if you say: "Sir, I have read all the medical books. Recognize me as a medical practitioner," no, that will be not.
So śrutayo vibhinnāḥ. Scriptures are different. Arguments, that is also not helpful. One man may argue better than me. Then philosophy: The philosophy, it is said, nāsau munir yasya mataṁ na bhinnam (CC Madhya 17.186). One philosopher is differing from another philosopher. Just now today Śyāmasundara has purchased one book about different philosophers. So that, you also cannot ascertain what is truth. Therefore śāstra says, dharmasya tattvaṁ nihitaṁ guhāyām. The truth is very confidential. So if you want to know that truth, mahājano yena gataḥ sa panthāḥ (CC Madhya 17.186), you should have to follow the great ācāryas. Then you will understand.
Therefore ācārya-upāsanā is essential. Ācārya-upāsanā is very essential. In all the Vedic śāstras the injunction is that. Tad-vijñānārthaṁ sa gurum evābhigacchet, śrotriyaṁ brahma-niṣṭham (MU 1.2.12). Tasmād gurum prapadyeta jijñāsuḥ śreya uttamam (SB 11.3.21). Anyone who is inquisitive to understand higher truths, he must surrender to guru. Tasmād guruṁ prapadyeta, jijñāsuḥ śreya uttamam. One who is inquisitive, who is now inquiring about transcendental subject matter, tad viddhi praṇipātena paripraśnena sevayā (BG 4.34). So all the śāstras says, in our Vaiṣṇava śāstra also Rūpa Gosvāmī says, ādau gurv-āśrayam: "In the first beginning, you must take shelter of a bona fide guru."