If anyone says that, "I am guru . . ." er, "I am God," then he cannot be guru, because he has no knowledge. How he is God? But he can cheat some people. That is different thing. You can cheat all people for some time and some people for all time, but not all people for all time. That is not possible.
So these kinds of guru, who poses themself that, "I am God," he's a false guru. The bona fide guru will say that, "I am servant of the servant of the servant of Kṛṣṇa," or God. Servant of. That is the business of guru. He serves Kṛṣṇa as Kṛṣṇa desires; that is his business. That is also not very difficult.
Kṛṣṇa says, Kṛṣṇa desires, sarva-dharmān parityajya mām ekaṁ śaraṇaṁ vraja (BG 18.66) that, "You give up all other engagement; just surrender unto Me, and I'll give you protection." Kṛṣṇa says. So guru's business is that, "You simply surrender to Kṛṣṇa." What is the difficulty? Simply repeat the same thing. Not for himself, but for Kṛṣṇa. He's bona fide guru.
So our this Kṛṣṇa consciousness movement is very bona fide because we say the same thing as Kṛṣṇa says. We don't make any addition, alteration. Not like big scholars like, "It is not to Kṛṣṇa . . ." Kṛṣṇa says, man-manā bhava mad-bhakto mad-yājī māṁ namaskuru (BG 18.65), and the scholar interprets, "It is not to Kṛṣṇa." Just see (the) foolishness. Kṛṣṇa directly says: "unto Me." He says, "Not to Kṛṣṇa." Misleading. Such misleading guru will not help you.
So therefore to find out a bona fide guru means that he does not change the words of Kṛṣṇa. That is his position. He places everything as it is, and he has understood thoroughly the science. Jijñāsuḥ śreya uttamam. Guru . . . what is the symptom of guru? Tasmād guruṁ prapadyeta jijñāsuḥ śreya uttamam (SB 11.3.21).
Those who are inquisitive to understand higher scientific knowledge, uttamam. Uttama means higher. Uttama, madhyama, adhama. There are three words: first class, second class, third class. So spiritual knowledge is uttamam. Anyone who is inquisitive to understand first-class knowledge, he requires to go to a guru. Those who are interested in third-class knowledge, they do not require any guru.
Third-class knowledge means animal knowledge: how to eat, how to sleep. How to make arrangement for eating, how to make arrangement for sleeping, that is third-class knowledge. Because the animal also try for this kind of knowledge, how to eat, how to sleep. Therefore this kind of knowledge is third-class knowledge.
And second-class knowledge is "What I am?" Athāto brahma jijñāsā. The Vedānta. That is second-class knowledge. And first-class knowledge, when he actually understands what he is—he is eternal servant of Kṛṣṇa—and engages himself in the service of the Lord, that is first-class knowledge. And therefore, as soon as he comes to the first-class knowledge platform, he becomes happy.