The good person out of the good treasure of his heart produces good, and the evil person out of his evil treasure produces evil, for out of the abundance of the heart his mouth speaks.
Jesus is the best authority on human motivation and behavior. And Luke's account of Jesus teaching in His "sermon on the plain" shows the wisdom and convicting insights that Jesus gives us. Who better to know us than our Creator? Who better to point out our biggest flaws and deepest need than our Savior? Jesus knows why we do what we do. We live and love from our hearts.
The heart, or inner man (or whatever you wish to call the immaterial part of us that is the sum of our thoughts, feelings, and will) is what drives our outward actions. The heart guides our speech. The heart moves our activity. In simple terms I see it this way... I do the things that I think about. And the evidence of that is in my life for all to see. Jesus says this with all confidence, declaring that good trees bring forth good fruit, implying that the impact of what each life produces will come directly from the outflow of the heart.
Jesus describes how the heart works with the compelling word "treasure". We hold our motivations as valued personal treasure deep within us. If we store up negative, sinful thoughts and feelings in the treasure box of the heart, sin will spill out as we speak and act. But if we fill up that same treasure chest in our chests with what is good, with God's truth and holy commitments, allowing Christ to remake us on the inside, our lives will show the good that Jesus is to the world.
I pause to place this valuable truth into my treasure chest today. May I let my mind ponder this simple but vital truth from Your lips so that I may treasure what is good. From that, would You by Your grace and Holy Spirit produce good in what I say and do today?