A faith based on mental ideas is brittle and subject to be shaken when those ideas are challenged, or overrun by the emotions or the impulsion of desire. The transformation of the being envisioned by the integral Yoga cannot rely solely on mental faith. In particular, the emotional being and the vital being need to also accept the faith in the spiritual path and the ultimate spiritual destiny, and thereby unify the major parts of the being around the common undertaking. It is also here not sufficient to accept a rigid and fixed faith that either leads to fanaticism or is unwilling and unable to change as the steps of the yogic process unfold and call one to adapt and grow under the spiritual impulsion.
Sri Aurobindo describes the limitations of an imperfect faith in the emotional being: “The heart too when it is troubled in its attachments and its certitudes, perplexed by throw-backs and failures and convictions of error or involved in the wrestlings which attend a call to move forward from its assured positions, has its draggings, wearinesses, sorrowings, revolts, reluctances which hamper the progress.”
The solution Sri Aurobindo recommends for the heart: “It must learn a larger and surer faith giving in the place of the mental reactions a calm or a moved spiritual acceptance to the ways and the steps of the Shakti which is in its nature the assent of a deepening Ananda to all necessary movements and a readiness to leave old moorings and move always forwards towards the delight of a greater perfection.”
Similarly, the vital being must find its proper faith as well: “The life mind must give its assent to the successive motives, impulsions, activities of the life imposed on it by the guiding power as aids or fields of the development of the nature and to the successions also of the inner Yoga, but it must not be attached or call a halt anywhere, but must always be prepared to abandon old urgency and accept with the same completeness of assent new higher movements and activities, and it must learn to replace desire by a wide and bright Ananda in all experience and action. The faith of the heart and the life mind, like that of the intelligence, must be capable of a constant correction, enlarging and transformation.”
Sri Aurobindo, The Synthesis of Yoga, Part Four: The Yoga of Self-Perfection, Chapter 18, Faith and Shakti, pp. 749-750