Have you ever looked into a mirror of curved glass that was designed to distort the image it reflects? Perhaps you are short and stocky, but in the glass you look tall and lean.

These “distortion mirrors” illustrate the human heart, which is totally unreliable in reflecting our spiritual condition. Our “heart mirror” is clouded with evil and completely awry with the serpentine twistings of the fall. It is wicked and deceitful above all things.

That being the case, our text then inquires, “Who can know it?” (Jer. 17:9). Certainly not man himself, for “he who trusts in his own heart is a fool” (Prov. 28:26). There is only One who can tell us anything about our true spiritual reflection, and that is God who searches our hearts (Jer. 17:10).

God, who knows, says we deceive no one but ourselves if we think we have no sin (1 Jn. 1:8). His Word clarifies the picture, for it is “a discerner of the thoughts and intents of the heart” (Heb. 4:12). Only as we measure ourselves by God’s standard will we see that we fall short of the glory of God. Only then will we realize the urgent necessity of salvation and accept His gracious offer of cleansing.