God wants to use everyone He calls fully. In order to do this, we have to learn and accept a painful and Christ-like characteristic. In order to be used fully, and we aren't talking about salvation, there is a particular characteristic we must accept. It is 100% against human nature.
Php 2:1-11
This mind, the mind of Jesus.
Jesus willingly accepted demotion, being humiliated by other people, w/o malice and bitterness.