"...The human heart cannot be seen by man. Only God knows for sure what is inside. We can have only a glimpse into the heart by observing what pours out into words, actions, and attitudes.
The tongue is just a muscle that does what it is told to do by the heart. The tongue cannot be brought under control by a heart that is out of control.
By learning how to ask specific questions, as a parent you can draw out of your child's heart the necessary data to help him biblically diagnose any sin problem that resides therein...You will be able to help him change not only his words, actions, and attitudes, but also (and more importantly) his thoughts and motives."
The Heart of Anger