“Make me your instrument” you pray. You ask this with the sincere desire to serve, and this is most laudable, but please realize that in order to be the perfect instrument, you must learn the art of surrender. The will is a wonderful gift from the Creator, but it does allow you to go off on your own tangents at times, does it not?
If you wish to be used by Spirit in service, this is a cooperative effort. Because you never have the big picture whilst you walk about in a human body, surrender is a necessary step. Does this mean that you become a puppet? Not at all. It means that you learn to attune to your inner guidance before acting. It means that you listen to and feel as well those subtle, loving urgings that tell and show you the best course of action. It is to these that you surrender.
You wish to be the perfect instrument? You are perfect already. It is merely a matter of a bit of fine tuning. The desire to fine tune your thoughts and actions is the perfect place to start.