Five thousand years ago Krsna said, sarva-dharman parityajya mam ekam saranam vraja: [Bg. 18.66] "You give up all other religious principles. Simply surrender unto Me." We are preaching the same thing. No change. There is no possibility of change. Then how Krsna is authority? So change means imperfect 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.
Lecture on Srimad-Bhagavatam 1.3.15, Los Angeles, September 20, 1972