What is the purpose of Sadhana (spiritual practices)?
To be yourself!
When prana level is low - you feel upset, angry, dejected and not so good. When prana level is even lower - you feel life is not worth living. When prana level is normal - you feel yourself, like a normal human being. When prana is a little higher than normal - you feel more creative, enthusiastic, and joyful. And if it is even higher, you realize something much deeper.
Sadhana is meant to increase this prana level in you. If your prana level is constantly high - then you don’t need to do sadhana - that is what is enlightenment; your optimum prana.
I remember an elderly gentleman, some 40 years back, asked me, "Are you tired? You must be tired!"
There was an 86 years old gentleman with me, he pounced on the person, suddenly saying, "Come on! A yogi will not get tired!" That is true! Tiredness is when our senses go outward; the moment the senses start turning inward, we are tapping into the eternal source of energy.