Inner strength means that you have the determination and the ability to persevere in the face of adversity.
Inner strength means that you have the quality of persistence when the going gets rough.
You demonstrate inner strength when you remain calm, cool, and relaxed during the job interview. If you are calm and cool during the interview, it is a good indication that you will be calm and cool in the inevitable crises that occur during the day-to- day operations of the company.