The heart is deceitful above all things, and desperately wicked: who can know it?
Many of us have become extremely skillful in arranging our lives so as to admit the truth of Christianity without being embarrassed by its implications.
We arrange things so that we can get on well enough without divine aid, while at the same time ostensibly seeking it!
We boast in the Lord but watch carefully that we never get caught depending on Him!
To many, Christ is little more than an idea, or at best an ideal: He is not a fact! They talk as if He were real and act as if He were not.
We can prove our faith by our committal to it—and in no other way!
Any belief that does not command the one who holds it is not a real belief: it is a pseudo belief only. And it might shock some of us profoundly if we were brought suddenly face-to-face with our beliefs and forced to test them in the fires of practical living!
What we need very badly these days is a company of Christians who are prepared to trust God as completely now as they must do at the last day. For each of us the time is surely coming when we shall have nothing but God!
Today is the best time to invite God to remove every false trust, to disengage our hearts from all secret hiding places, and to bring us out into the open where we can discover for ourselves whether we actually trust Him. This is a harsh cure, but it is a sure one!
17:9 heart. A metaphor for the human will and emotions (cf. vv. 5–7). deceitful. Tortuous, uneven, and crooked like a bad road. desperately sick. Medically incurable (15:18; 30:12, 15; Job 34:6; Isa. 17:11; Mic. 1:9). who can understand it? A rhetorical question expecting a negative answer. However, this strongly negative assessment of the human heart is not intended as a description of the heart of a believer under the new covenant, where God promises to write his law on people’s hearts (Jer. 31:33; 32:40; cf. Ezek. 36:26; Rom. 5:5; 6:17; Heb. 10:22; 1 John 3:21).
17:9 The heart is deceitful more than anything else Refers to human thoughts and feelings. The Hebrew term for the heart metaphorically refers to a person’s inner life—the will, thoughts, motivations, and emotions. This is a different understanding than “heart” in modern Western thinking, which primarily indicates the seat of emotions.
Who can understand it? Only Yahweh understands the thoughts and motivations of His creation (Jer 17:10).
17:9 The heart. In the OT, the “heart” is more than the seat of emotion. It represents the basis of character, including the mind and the will (4:19; Prov. 4:23; 16:23). See theological note “Free Will.”
Every choice that we make in life we make for some reason. Our decisions are based upon what seems good for us at the moment, all things considered. We do some things out of intense desire. We do other things with no awareness of desire at all. Yet the desire is there or we wouldn’t choose to do them. This is the very essence of free will—to choose according to our desires.
Jonathan Edwards, in his work The Freedom of the Will, defines the will as “that by which the mind chooses.” There can be no doubt that human beings do indeed make choices. I am choosing to write; you are choosing to read. I will to write, and writing is set in motion. When the idea of freedom is added, however, the issue becomes terribly complicated. We have to ask, freedom to do what? Even the most ardent Calvinist would not deny that the will is free to choose whatever it desires. Even the most ardent Arminian would agree that the will is not free to choose what it does not desire.
With regard to salvation, the question then becomes, what do human beings desire? The Arminian believes that some desire to repent and be saved. Others desire to flee from God and thus reap eternal damnation. Why different people have different desires is never made clear by the Arminian. The Calvinist holds that all human beings desire to flee from God unless and until the Holy Spirit performs a work of regeneration. That regeneration changes our desires so that we will freely repent and be saved.
It is important to note that even the unregenerate are never forced against their will. Their wills are changed without their permission, but they are always free to choose as they will. Thus we are indeed free to do as we will. We are not free, however, to choose or select our nature. One cannot simply declare, “Henceforth I will desire only the good” anymore than Christ could have declared, “Henceforth I will desire only evil.” This is where our freedom stops.
The Fall left the human will intact insofar as we still have the faculty of choosing. Our minds have been darkened by sin and our desires bound by wicked impulses. But we can still think, choose, and act. Yet something terrible has happened to us. We have lost all desire for God. The thoughts and desires of our heart are only evil continuously. The freedom of our will is a curse. Because we can still choose according to our desires, we choose to sin and thus we become accountable to the judgment of God.
Augustine said that we still have free will, but we have lost our liberty. The royal liberty of which the Bible speaks is the freedom or power to choose Christ as our own. But until our heart is changed by the Holy Spirit, we have no desire for Christ. Without that desire we never will choose Him. God must awaken our soul and give us a desire for Christ before we will ever be inclined to choose Him.
Edwards said that as fallen human beings we retain our natural freedom (the power to act according to our desires) but lose moral freedom. Moral freedom includes the disposition, inclination, and desire of the soul toward righteousness. It is this inclination that was lost in the Fall.
Every choice I make is determined by something. There is a reason for it, a desire behind it. This sounds like determinism. By no means! Determinism teaches that our actions are completely controlled by something external to us, making us do what we don’t want to do. That is coercion and is opposed to freedom.
How can our choices be determined but not coerced? Because they are determined by something within—by what we are and by what we desire. They are determined by ourselves. This is self-determination, which is the very essence of freedom.
To be sure, for us to choose Christ, God must change our heart. That is precisely what He does. He changes our heart for us. He gives us a desire for Himself that we otherwise would not have. Then we choose Him out of the desire that is within us. We freely choose Him because we want to choose Him. That is the wonder of His grace.
 Tozer, A. W., & Smith, G. B. (2015). Evenings with tozer: daily devotional readings. Chicago, IL: Moody Publishers.
 Crossway Bibles. (2008). The ESV Study Bible (pp. 1405–1406). Wheaton, IL: Crossway Bibles.
 Barry, J. D., Mangum, D., Brown, D. R., Heiser, M. S., Custis, M., Ritzema, E., … Bomar, D. (2012, 2016). Faithlife Study Bible (Je 17:9). Bellingham, WA: Lexham Press.
 Sproul, R. C. (Ed.). (2015). The Reformation Study Bible: English Standard Version (2015 Edition) (pp. 1292–1293). Orlando, FL: Reformation Trust.