Just like in law books, there is some law made already. Whimsically you cannot, I mean to say, erase the words and put something that, "It should be changed like this." That will not be accepted. Law, if there is change . . . actually, there is no change. There cannot be change. Real law means there is no change. Just like day and night, it is coming. The fortnight, the dark period and the light period, it is coming for millions and millions and time immemorial. The same law is going, going on. You cannot change. So as soon as you change, that means it is imperfect. You change.
So Vedic laws are not like that. You cannot change. Five thousand years ago Kṛṣṇa said, sarva-dharmān parityajya mām ekaṁ śaraṇaṁ vraja (BG 18.66): "You give up all other religious principles. Simply surrender unto Me." We are preaching the same thing. No change. No change. There is no possibility of change. Then how Kṛṣṇa is authority? So change means imperfect knowledge. This very change. And perfect knowledge . . .
You will find that one who is very experienced medical practitioner, he gives you a prescription, and you visit him again and again, he gives you the same prescription, unless you are cured. His prescription is so nice that he doesn't change. But a nonexperienced physician, every time you go, he will change the prescription. But actually, those who are experienced, he knows, "This is the disease, and ultimately this medicine will cure. So let him repeat that medicine."
So our is that platform. Harer nāma harer nāma harer nāmaiva kevalam (CC Adi 17.21). We repeat only. We don't change: "Now hari-nāma is not curing, so let me add, instead of Hare Kṛṣṇa, 'John Kṛṣṇa,' if I may." No. No "John Kṛṣṇa." (laughter) That same Hare Kṛṣṇa must be repeated. And you will be cured. So change means imperfect knowledge. No change means that is perfect knowledge. So we follow that "no change" policy. No, not that because I think I have become now advanced, I change this to that. That means I am not advanced. My knowledge is imperfect; therefore I am changing.