I know that when I have lived "out of character," opting to do things I knew to be wrong, I was really acting "in character," willfully so. I can't claim that the sins I have willfully or knowingly committed were aberrations. They were expressions of my fallen human nature and so, consistent with my fallen character.
That's why I ask God everyday to show me my sins, lead me to repentance, and empower the Holy Spirit to help me amend my ways. I want my character to be more and more like that of Jesus. Psalm 139:23-24 are important verses of Scripture to me:
Search me, O God, and know my heart;Read this excellent piece on character by Cindy Hess Kasper. But be sure to read Job 1:13-21 first. (The "his" in the first sentence of the passage from Job refers to Job himself.)
test me and know my thoughts.
See if there is any wicked way in me,
and lead me in the way everlasting.