The heart is deceitful above all things and beyond cure. Who can understand it? “I the Lord search the heart and examine the mind, to reward each person according to their conduct, according to what their deeds deserve.”

a. The heart is deceitful above all things: Trusting the heart is just another way of trusting in man. To this point, the Prophet Jeremiah has given some reason to be cautious about the inclinations and direction of the heart. He noted how the evil heart of the people of Judah had led them astray.

· Yet they did not obey or incline their ear, but everyone followed the dictates of his evil heart. (Jeremiah 11:8)

· They prophesy to you a false vision, divination, a worthless thing, and the deceit of their heart. (Jeremiah 14:14)

· Each one follows the dictates of his own evil heart, so that no one listens to Me. (Jeremiah 16:12)

b. The heart is deceitful above all things: Our hearts often deceive us, presenting heart-fulfillment as the key to happiness. What we desire is often not what we need. The advice “be true to your heart” fails when the heart is deceitful above all things.

i. “In the OT usage the heart signifies the total inner being and includes reason. From the heart come action and will.” (Feinberg)

ii. “The pravity and perversity of the man’s heart, full of harlotry and creature confidence, deceiving and being deceived, is here plainly and plentifully described; and oh that it were duly and deeply considered.” (Trapp)

c. And desperately wicked: The heart is not only deceitful, but also wicked – and desperately so. Many have been led to rebellion, disobedience, and great sorrow by following their heart, without challenging their heart and judging it by the measure of God’s truth. “Follow your heart” is poor advice when the heart is desperately wicked.

i. The sense of the Hebrew for desperately wicked seems to have sickness more than depravity in mind. “Unregenerate human nature is in a desperate condition without divine grace, described by the term gravely ill in verse 9 (RSV desperately corrupt, NEB desperately sick).” (Harrison)

ii. For the believer under the New Covenant, we have a new heart (Ezekiel 36:26), are a new creation (2 Corinthians 5:17), and a new man patterned after Jesus (Ephesians 4:24, Colossians 3:10). Still, there is an element of sin and flesh that remains in the believer. Since Jeremiah used the term heart in a general sense, we can say that our identity is not deceitful and desperately wicked; yet we still have to deal with an element of inward deceit and wickedness.

d. Who can know it: The heart’s deceit and wickedness are advanced enough that even the individual may not know or understand their own heart, and outsiders have even more difficulty in discerning the heart of others.

e. I, the LORD, search the heart, I test the mind: Though knowing the heart of one’s self or others is difficult and sometimes impossible, God searches, tests, and knows the heart and mind. It is wise to trust what God says about us more than what we think or feel about ourselves.

i. I test the mind: “A second word is here set in parallel to heart, literally, ‘kidneys’, hidden depths. These, Yahweh assays or ‘tests’…the two terms ‘heart’ and ‘kidneys’ cover the range of hidden elements in man’s character and personality. Nothing is hidden from Yahweh.” (Thomspon)

ii. “The Lord is called by his apostles, Acts 1:24, kardiognōstēs, the Knower of the heart. To him alone can this epithet be applied; and it is from him alone that we can derive that instruction by which we can in any measure know ourselves.” (Clarke)

f. Even to give to every man according to his ways: Because God perfectly knows the heart and mind of man, His judgment is true. God knows to what extent the heart either justifies or condemns the doings of a man or woman.