On Bhagvad Gita: Yoga is freedom from that which you think yourself to be

न हि ज्ञानेन सदृशं पवित्रमिह विद्यते ।

तत्स्वयं योगसंसिद्ध : कालेनात्मनि विन्दति ।।

~ श्रीमद भगवद गीता (४. ३८)

Certainly, there is no purifier in this world like Knowledge.