The vital’s eagerness and its vairagya are shadows of this faith, forms which it has taken in order to keep the vital from giving up in spite of the pressure of despondency and struggle. Even in the mind and vital of the man of strongest mental and vital faith there are periods when the knowledge in the psychic gets covered up—but it persists behind the veil.
In you the eclipse has been strong and long because, owing to certain mental and vital formations, the assent of the mind and vital got clouded over and could only take negative forms. But there is always the knowledge or intuition in the soul that started you on the way. I have been pressing on you the need of faith because the assent has again to take a positive form so as to give free way to the Divine Force; but the persistent drive in the soul (which is a hidden and externally suppressed faith) is itself sufficient to warrant the expectation of the Grace to come.
Ref: Letters on Yoga Vol. I