Every person in the Bible whom God used in a mighty way had to go through an “emptying of self.” God could then work through them using His Power to accomplish supernatural things. But it’s a waste of time, energy, and resources to try to do something that is supernatural when you are not allowing God to work through you in a supernatural way.

http://who-god-is.com/emptying-of-self-is-not-easy-but-worth-it