Answer
The simple answer, as given by A. C. Bhaktivedanta Swami Prabhupada, is this: why does the question even arise—“whom should I hear?” It is sufficient to hear from your own spiritual master. Be loyal, stay fixed, and hear from him.
Do not think that he has not already given everything necessary for your advancement. Sometimes the mind says, “Maybe I need something more… maybe I should learn about my siddha identity from somewhere else.” But this is not required at our stage.
There is an instance where some disciples were trying to read higher topics about siddha-deha and advanced literature. When asked about it, Prabhupada clearly instructed: “You do what I have told you. At the right time, everything will be revealed.”
This is a transcendental process. It is not a mechanical or intellectual exercise of collecting information from different books or sources. Real understanding unfolds from within, by practice and sincerity, because the Lord is seated in the heart.
So the principle is simple: remain steady, follow the instructions of your spiritual master, and trust that whatever needs to be revealed will come at the proper time.
