Sings Bhagavad Gita:

न हि ज्ञानेन सदृशं पवित्रमिह विद्यते ।
तत्स्वयं योगसंसिद्धः कालेनात्मनि विन्दति ॥४-३८॥

na hi jñānena sadṛśam
pavitram iha vidyate,
tat svayam yogasamsiddhaḥ
kālenā’tmani vindati (38)

“Doubtlessly nothing in the world is more purifying than this spiritul knowledge and your heart will realize it spontaneously when you have attained to perfection on the Way of Action.”

Nothing in this world purifies as this knowledge does. And this knowledge will be manifest to the doer alone, not to anyone else, when his practice of yog has reached maturity, not at its inception, not in the middle, not externally but within his heart-within his Self.

Humble Wishes!!!