He must also do what is necessary to acquire good character qualities (middos) and avoid the opposite. A person may not say, "I'll trust You Hashem to teach me to be patient." He has to train himself to overcome his anger and not be impetuous. He may not say, "I'm going to trust Hashem to keep me from being prideful and arrogant." No, he has to work on himself and become modest and humble. He has to change his middos by himself. He may not leave it up to Hashem. -- Ohr Avigdor Shaar Bitachon.