We live in a time when most people think that by saying, "I have a good heart" it exonerates them from bad decisions.  They are in effect saying that as long as my intent was right, it doesn't matter what I did to you, thereby attempting to evade the accountability.  I had a discussion a few years ago with a colleague about whether it is possible to know what is in a persons heart.  Her answer was that only Jesus knew.  Mine was to watch what they say and do.  Jesus tells us in the Gospel of Matthew that out of the abundance of the heart the mouth will speak (12:34).  I think that only the depth of a person's heart evades the observer.  The thing that is abundant will always come out in the speech.  If one is a racist, it won't take long for the views to surface.  If one is a misogynist, before long female bashing will surface.  That's why whenever I am trying to get to know someone I like to have a coffee so that we can sit for a while and talk.  Eventually, that person's values will come out in the conversation enough to make a judgment.  Our scripture today admonishes us to guard our heart.  How do we do that?  Sometimes it requires purging some things we've learned growing up.  Sometimes it requires having a made up mind about what we watch on television or listen to by radio.  It definitely requires having a prayer life where we are able to commune with Jesus telling him the things that are important to us most and asking for help in the things that are of import to him.  Hiding, like the psalmist (119) the word of God in our heart that we might not sin against God. Selah.