ISKCON might have some secrets, but the secret we should concern ourselves is that the secret to developing faith in Krsna is hearing.
Krsna inhabits His pastimes. When He is praised, Krsna is present in full. When He speaks, Krsna is there 100%, present in that sound of His words.
So the more we choose to practice this hearing, either from Krsna or our beloved Srila Prabhupada, then we are in Krsna’s actual presence, though imperceptible in the beginning stages. As we associate with Krsna Personally simply by this hearing, Krsna gradually becomes manifest in our hearts.
Finally, when we are convinced how strong and powerful Krsna is in all these situations we are hearing about, How Krsna’s knowledge is immeasurable, how utterly capable Krsna is to do anything great, we slowly become willing to place our lives in Krsna’s care.
One can become fully Krsna conscious and develop this complete faith in Krsna only through this hearing process in the association of Krsna’s pure devotee(in almost all cases- but in rare cases through special mercy). This transcendental process of cultivating Krsna consciousness through submissively hearing from the purely realized souls like Srila Prabhupada is always there and under the protection of Krsna’s internal potency, and is therefore not affected by the three modes of material nature. In other words, it cannot be checked by any material circumstance.
So whatever temporary intrigue is going on in your devotional and material lives, and no matter what problems are perceived in the management of a particular religious organization, it cannot check your advancement in Krsna consciousness.
Srila Prabhupada said to just persevere, “step by step by step” (and one day we will finally see Krsna). He also once said that unless we read (hear) enough, we cannot stick it out in the long run. After 20 years or 40, or 50 years, we will need a strong foundation in the philosophy by this constant and attentive hearing to give us the impetus to continue, long after the sentiments have worn off.
“A person who is constantly engaged in reading literature enunciating the cultivation of Vaisnava devotional service is always glorious in human society and certainly Lord Krsna becomes pleased with him. A person who very carefully keeps such literature at home and offers respectful obeisances to it becomes freed from all sinful reactions and ultimately becomes worshipable by the demigods”
(Skanda Purana)