"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."

Luke 6:45, ESV

As a Christian writer, I have had the privilege of hearing great feedback from people who read my writing, but I have also received some harsh criticism. Probably one that still makes me chuckle today is being called a false prophet for reasons I cannot understand. But knowing that there is a lesson to be learned in everything, I started asking myself this question: "What makes a false prophet a false prophet?"

Jesus, addressing the crowds, actually spoke of false prophets and their greatest distinction. We think what makes a false prophet is his or her teaching, doctrine, behavior or even followers. While all of those things can be likely indications, Jesus gives us the ultimate indicator of a false prophet in Luke 6:45: the heart.

A quick cross-reference to Matthew's version tells us this in Matthew 7:16: "You will recognize them by their fruits. Are grapes gathered from thornbushes, or figs from thistles?" (ESV). The heart heavily determines whether our actions become that of a God-honouring, Christ-following disciple or an extremely passionate but sincerely wrong false prophet.

That's why the heart matters to God because it can very much affect everything we are and do. Proverbs 4:23 tells us this: "Keep your heart with all vigilance, for from it flow the springs of life" (ESV). Matters of the heart are serious matters to God and should be serious to us as well.

Today, however, we live in a culture that does not take the heart seriously. The default is always to look at the surface—the image, the reputation, the face value—of things and people, judging their sincerity based on how they manifest on the outside. Anyone can deceive with the appearance, but the heart motive can never point to a lie.

That's why God instructed Samuel—and consequently all of us today, too—to judge according to the heart and not the outward appearance in choosing the anointed leader of a country (1 Samuel 16:7). That's why David, after falling into sin, asked God to create in him first a clean heart.

God takes heart matters seriously because they act like rudders that may be small and seemingly insignificant but steer a whole ship into a course. Consequently, God asks us to take the heart seriously—to guard our own hearts and to be vigilant of the heart motives of others.