Luke 9:38-41 Suddenly a man from the multitude cried out, saying, “Teacher, I implore You, look on my son, for he is my only child. And behold, a spirit seizes him, and he suddenly cries out; it convulses him so that he foams at the mouth; and it departs from him with great difficulty, bruising him. So I implored Your disciples to cast it out, but they could not.” Then Jesus answered and said, “O faithless and perverse generation, how long shall I be with you and bear with you? Bring your son here.”
We have been given authority over demons and spirit of boldness. Luke 9:1 Then He called His twelve disciples together and gave them power and authority over all demons, and to cure diseases. We must learn to exercise the power and authority we have over demons and sickness. 2 Timothy 1:7 For God has not given us a spirit of fear, but of power and of love and of a sound mind.