In plain words
Faith in the Ātma is most necessary to man. It is for lack of it that man turns into a demon. He sinks into weakness. The ancients won everything through faith in the Ātma. Faith in the Ātma is the root of all welfare and all Ānanda. Lose that faith and one falls. Viśvāsa, faith, is our śvāsa, our breath. Without breath we are no better than a śava, a corpse. With breath we are equal to Śiva. Faith is our Śiva-nature, our being endowed with all power. It is perfect. The Ātma is perfect by its own nature. No other sādhana is needed to attain it. Faith in the Ātma alone is enough.