What’s needed for Perfection?

As I have said already, in all matters, work and study as well as in the inner progress in the yoga, the same thing is needed if you want perfection—quietude of mind, becoming aware of the Force, opening to it, allowing it to work in you. To aim at perfection is all right, but restlessness of mind is not the way towards it. To dwell upon your imperfections and be always thinking how to do and what to do, is not the way either. Remain quiet, open yourself, allow the consciousness to grow—call the Force to work. As it grows and as the Force works, you will become aware not only of what is imperfect, but of the movement which will take you, (not at one step, but progressively) out of the imperfection and you will then only have to follow that movement.

If you overstrain yourself by too prolonged work or a restless working, that disturbs or weakens the nervous system, the vital-physical, and lays one open to the action of the wrong forces. To work but quietly so as to have a steady progress is the right way.

Ref  : Letters on Yoga Vol. II