Psalms 139: 23 Search me, O God, and know my heart;    test me and know my anxious thoughts.
Psalms 139:24
Point out anything in me that offends you,     and lead me along the path of everlasting life.

Knowing your heart
Your character is not revealed by your actions, but by your reactions. Actions can be planned- but reactions are spontaneous!
They give you a glimpse of what is really in your heart so that you can look at it and deal with it. The most dangerous lies are not the ones we tell other people; they are the ones we tell ourselves and learn to live with comfortably.