So our Krsna consciousness movement is very simple. We haven’t got to manufacture anything, any philosophy, by research work. Krsna says, yogah proktah puratanah [Bg. 4.3]. We have to speak the same thing. The most…, very, very old: puratanah. We haven’t got to manufacture it. Nowadays we have advanced in education and civilization; therefore we have to concoct some idea. It is not our business. We have to speak the same old puratanah thing. What is that puratanah thing? Five thousand years ago, Krsna says, “Surrender unto Me.” So we have to preach this old gospel, “Surrender unto Krsna. Finish your business.” Krsna says, “I am speaking that old thing which millions of years ago I spoke to sun-god.” Similarly, we have to refer to Krsna: “Five thousand years ago, Krsna said this; let us repeat that.”Yogah proktah puratanah. And who can speak this? Bhakto ‘si — one who is actually devotee. Others, rascals, they interpret Bhagavad-gita in different ways. They are not speaking the puratanah; therefore they are null and void, they are rejected. Sa kaleneha yogo nastah [Bg. 4.2]. One who does not speak the whole thing by the parampara system is speaking nonsense. Take evidence from Bhagavad-gita — sa kaleneha nastah [Bg. 4.2]. Krsna said that “The old parampara system, as I spoke to sun-god,”

sa kaleneha mahata
yogo nastah parantapa
[Bg. 4.2]

As soon as we deviate from the parampara system… Parampara system means to receive the knowledge through disciplic succession — very simple thing. But in due course of time it becomes deviated. Just like nowadays they are interpreting Bhagavad-gita in different ways. That means kalena nasta. This is not Bhagavad-gita. Anyone who is speaking against Krsna, they are discovering some new meaning, adhyatmika meaning. They say adhyatmika meaning. Do they not say like that, adhyatmika meaning? What is this nonsense, adhyatmika meaning? That means kalena nastah. Anyone who discovers some adhyatmika meaning of Bhagavad-gita, according to his fertile brain, that sort of preaching of Bhagavad-gita is nastah. It is not real Bhagavad-gita. Real Bhagavad-gita is if you speak the very old thing:

sarva-dharman parityajya
mam ekamsaranam vraja
[Bg. 18.66]

What Krsna said five thousand years ago in the Battlefield of Kuruksetra, if you speak that old thing, that “Krsna desires that everyone surrender unto Him, so let me preach this cult: ‘My dear friend, please surrender to Krsna,’ ” then you are a good preacher. Three words — “My dear friend, please surrender to Krsna.” That’s all. To become a preacher in Krsna consciousness movement is not at all difficult. We have to speak the same thing. This is confirmed by Caitanya Mahaprabhu:

yare dekha, tare kaha ‘krsna’-upadesa
amara ajnaya guru hana tara’ ei desa
[Cc. Madhya 7.128]

Yare dekha, tare kaha ‘krsna’-upadesa — this is guru. Guru does not mean anything extraordinary. Any damn rascal like me can become guru.

From Srila Prabhupada’s lecture on Bhagavad-gita 4.3 — February 10, 1974, Vrndavana