Jñāna means knowledge that, "I am not this body. I am spirit soul." This jñāna can be attained by tapasya. Tapasya means austerity. And if we attain knowledge and undergo austerities, then we become purified. Therefore:
- vīta-rāga-bhaya-krodhā
- man-mayā mām upāśritāḥ
- bahavo jñāna-tapasā
- pūtā mad-bhāvam āgatāḥ
- (BG 4.10)
That the whole aim is how to get out of this material attachment, and in our spiritual body, we go back to home, back to Godhead.
Actually, at the present moment, there is no education of the understanding of spiritual life. Everyone is interested with this material body only. Nobody is educated, neither interested in the spiritual life. But unless you take interest in spiritual life, our this material condition of miserable life will continue.