Paramam guhyam is most confidential, that this teaching of Lord Krsna, that "You give up all religion, all occupation,"sarva-dharman parityajya [Bg. 18.66]. "Simply surrender unto Me." It is possible… It is not possible to take this advantage by everyone. It is practical. If I would have said that "You give up Christian religion and you take to this Krsna consciousness" in the first, you would have immediately left the meeting. So it is very confidential; it is not to be opened immediately. When gradually one comes to confidence, then it will be clear.
Srila Prabhupada; Lecture on Srimad-Bhagavatam 6.2.46
Magha-mela, Prayag, January 30, 1971