Inner Strength Meaning

(idiomatic) Integrity of character; resoluteness of will; mental resistance to doubt or discouragement.

Example: 1873, Anthony Trollope, The Eustace Diamonds, ch. 28:
  In any trouble, such as was this about the necklace, there would come over his face a look of weakness which betrayed the want of real inner strength.
1919, John Galsworthy, Saint's Progress, ch. 1:
  To do as your aunt and uncle in their kindness wish, would, I am sore afraid, end in depriving you of the inner strength and happiness which God only gives to those who do their duty and try courageously to repair their errors.
2008 Aug. 28, Michael Kinsley, "Everybody Knows the Trouble I've Seen," Time:
  First, it says the candidate has the inner strength or the wisdom or whatever it takes to address the unpredictable challenges he or she will face if elected.