Firm and Constant Will is Needed

It is quite sufficient if there is the firm and constant will towards faith and self-offering. It is understood that it is not possible for the human nature to be always without movements of doubt, obscurity or things not yet offered until the inner consciousness has sufficiently grown to make these impossible. It is because it is so that the will is necessary so that the Force may work to remove these things with full consent and will of the mind and heart of the sadhak. To try to reject these things and make the will permanent is sufficient,—for it is this effort that brings eventually the permanence.

Ref : Letters on Yoga Vol. II