There are a few differences that are key when distinguishing between a person’s heart and their behavior. When addressing the behavior, we tend to be rather narrow, not really caring about underlying beliefs and motives and such. It is imperative that we look at and address a person’s attitudes, motives, emotions, and beliefs. These things are pretty important in regards to addressing the heart, but, I must caution that of course we do not know people’s hearts the way God does, and we should not pretend to. It is true that you can judge a book by its cover, nonetheless, we must still be careful about doing so. “By their fruit you will recognize them. Do people pick grapes from thorn bushes, or figs from thistles?” (Matthew 7:16)
“Even a child is known by his actions, by whether his conduct is pure and right.” (Proverbs 20:11). These are very important concepts that we find in Scripture, and for some reason people really don’t like it. People love to say things like, “Don’t judge me, you don’t know my heart.” Well, this is true really, God knows your heart, we do not have the kind of knowledge he has; however, there is a inextricable connection between one’s heart and one’s behavior. Our Lord said that the words of our mouths are the overflow of our hearts. However, I believe an important distinction is when addressing things would be that when you address only the external behavior, you don’t really care or love the person. What you really care about is that you are inconvenienced, or sinned against, or embarrassed or something along them lines. You tell the person to do this, or not do that, but you never explain why, never try to correct wrong thinking, so on and so forth. If you’re not willing to get on your knees and labor hard there, then more than likely you only care about the external inconvenience, as opposed to truly loving and attempting to change the heart. I may be wrong on these things, please feel free to provide input and thoughts. They are my reflections on the subject thus far, and I have been known to change them.