If anyone is able to answer about the science of Kṛṣṇa, he is spiritual master. He is spiritual master. It doesn't matter where he's born or what he is, whether he's a brāhmaṇa, or a śūdra, or an American or an Indian or whatever he is. Never mind.
Just like . . . it is practical. When you go to a doctor, medical practitioner, you do not ask, "Well, Doctor, are you American or Indian? Are you brāhmiṇ? Are you Jew? Are you Christian?" No. Oh, he has got the qualification of a medical man, so you surrender: "Doctor, treat me. I am suffering." So there is no question. So Caitanya Mahāprabhu has given liberal, that "Anyone who knows the spiritual science, or the Kṛṣṇa science . . . Kṛṣṇa science is spiritual science. Because Kṛṣṇa is the ultimate goal of spiritual science. When I speak of Kṛṣṇa, you must remember that I am speaking of God. There are millions of name of God in different parts of the world, but "Kṛṣṇa" is the supreme name according to Vedic knowledge.
So therefore Lord Caitanya has recommended, and His recommendation is accepted by the authorities even at the present moment:
- kibā śūdra, kibā vipra, nyāsī kene naya
- yei kṛṣṇa-tattva-vettā sei 'guru' haya
- (CC Madhya 8.128)
And you'll be surprised that Lord Caitanya's principal disciples were all so-called fallen in the society. He appointed one Haridāsa Ṭhākura, Nāmācārya Haridāsa Ṭhākura. This Haridāsa Ṭhākura was a Muhammadan. He happened to take his birth in a Muhammadan family, but he became a follower of Caitanya, and Caitanya Mahāprabhu, after training him, He gave him the highest post of His spiritual mission.