Bad thoughts separate you from others and make you forget the divinity. So you must combat evil thoughts arising in your mind.
As soon as thoughts come to you, you should not rush into action, but use your intelligence and arrive at a correct decision.
Action taken after scrutiny results in peace.
The root cause of fear in man is the absence of pure and sacred thoughts in his mind.
However learned and powerful a person be, if he is not virtuous, he will succumb to his weaknesses.
Shirdi Sai Baba