Dr. M.R.Dehaan tells of a conversation with a neighbor in which he really got to the heart of things: “It was the first time I met my neighbor, who had just moved in a few days before. He told me he had heart trouble and had sold his business on the advice of his doctor. He seemed quite surprised when I said, ‘Yes, I know, and I understand you were born with a bad heart.’ Emphatically he replied, ‘Oh no, I had a heart attack just a year ago! Before that my heart was perfect.’ ‘But,’ I added, ‘I read just this morning that you were born with heart disease.’ I referred him to what God says about the sinful human heart and the need of a new heart. It was the first time he had heard the real diagnosis of his heart condition. My good neighbor had physical heart trouble, but his spiritual heart condition was a much more serious problem.” Dr. Dehaan had an accurate prescription: “There is only one remedy. A ‘new heart’ must be supplied by the Great Physician, Jesus. He does His work in us as we acknowledge our heart trouble and let Him operate by His grace and give us eternal life.”
This leads us to the question, What is the nature of the believer’s new heart? This aspect of our life must be important; it is referred to over 750 times in the Scripture. For example, Proverbs advises “Keep your heart with all diligence, For out of it spring the issues of life” (Prov. 4:23). The heart’s importance is also indicated in the greatest commandment: “You shall love the LORD your God with all your heart, with all your soul, and with all your mind” (Matt. 22:37).
In his book, Religious Affections, Jonathan Edwards made a strong case for the central role of the heart in Christian life and worship. Here is an excerpt: “That religion which God requires, and will accept, does not consist in weak, dull, and lifeless wishes, raising us but a little above a state of indifference: God, in his word, greatly insists upon it, that we be good in earnest, ‘fervent in spirit,’ and our hearts vigorously engaged in religion: Rom. 12:11, ‘Be ye fervent in spirit, serving the Lord.’ Deut. 10:12, ‘And now, Israel, what doth the Lord thy God require of thee, but to fear the Lord the God, to walk in all his ways, and to love him, and to serve the Lord thy God with all thy heart, and with all thy soul?’ and chap. 6:4, 6, ‘Hear, O Israel, the Lord our God is one Lord: And thou shalt love the Lord thy God with all thy heart, and with all thy might.’ It is such a fervent vigorous engagedness of the heart in religion, that is the fruit of a real circumcision of the heart, or true regeneration, and that has the promises of life; Deut. 30:6, ‘And the Lord thy God will circumcise thine heart, and the heart of thy seed, to love the Lord thy God with all thy heart, and with all thy soul, that thou mayest live.(KJV)’ 
A study of biblical passages mentioning the “heart” indicates that it corresponds to person’s innermost being–especially as it relates to affections and love. The heart reflects what is valued and treasured in life.
Hebrews 4:14 indicates that the inner, unseen you is comprised of soul and spirit: “For the word of God is living and powerful, and sharper than any two-edged sword, piercing even to the division of soul and spirit…” Is heart identical with either soul or spirit? Not exactly; nor is the”heart” an additional “part” of us. Rather, the heart is the seat of the affections in both soul and spirit. 
However, references to the believer’s heart are mixed. Some refer to sinful tendencies, other passages describe the new, righteous heart. How do we reconcile these differences? Just as the physical organ of the heart has chambers, consider two chambers of the believer’s heart: the “soul chamber” and the “spirit chamber.”
The Soul Chamber of the Heart
The soul chamber of the heart is subject to the influence of the flesh, the world, and the devil. References of warning are addressed to soul/heart. When referring to the flesh tendencies in the soul chamber, the prophet declared, “The heart is deceitful above all things, And desperately wicked; Who can know it?”(Jer. 17:9). Similarly, the apostle Paul confessed that in our flesh “dwells nothing good” (Rom. 7:18; Cf. Matt. 15:19).
Other passages are directed at the soul’s potential and choice to love and value either what is evil (Deut. 11:16; Psalm 66:18) or what is good (Cf. James 4:8; 1 Peter 1:22; 3:15; Prov. 28:26; Col. 3:15.) Our Lord instructed, “Do not lay up for yourselves treasures on earth, where moth and rust destroy and where thieves break in and steal; but lay up for yourselves treasures in heaven, where neither moth nor rust destroys and where thieves do not break in and steal. For where your treasure is, there your heart will be also” (Matt. 6:19-21). “If ye then be risen with Christ, seek those things which are above, where Christ sitteth on the right hand of God. Set your affection on things above, not on things on the earth” (Col. 3:1,2).
The Spirit Chamber of the Heart
The spirit chamber of the heart has been made a new creation in Christ (2 Cor. 5:17). This is the inner man that “delights in God’s law” (Rom. 7:22). The spirit/heart was cleansed by faith at salvation (Acts 15:9). This chamber is referred to in passages such Ezekiel’s prophecy of regeneration: “Then I will sprinkle clean water on you, and you shall be clean; I will cleanse you from all your filthiness and from all your idols. I will give you a new heart and put a new spirit within you; I will take the heart of stone out of your flesh and give you a heart of flesh. I will put My Spirit within you and cause you to walk in My statutes, and you will keep My judgments and do them.” (Ezek. 36:25-27) And Jeremiah anticipated this heart change through the New Covenant: “But this is the covenant that I will make with the house of Israel after those days, says the LORD: I will put My law in their minds, and write it on their hearts; and I will be their God, and they shall be My people” (Jer. 31:33; Cf.John 7:38; Matt. 12:35 KJV).
As the believer knows and reckons true his identification with Christ, he appreciates his new heart, in which he has become a partaker of the divine nature (2 Pet. 1:4).
This new heart calls us to love God supremely. The Song of Solomon portrays a poetic, middle eastern testimony of potential intimacy in Godly married life. The bride declared, “Set me as a seal upon your heart, As a seal upon your arm; For love is as strong as death, Jealousy as cruel as the grave; Its flames are flames of fire, A most vehement flame. Many waters cannot quench love, Nor can the floods drown it. If a man would give for love All the wealth of his house, It would be utterly despised” (Song 8:6,7). As the Shulamite shared her heart with her groom, so the bride of Christ should reflect the Bridegroom’s matchless love.
A United Heart
Therefore, our prayer should be for a united heart–one in which the “soul chamber” is in agreement with the “spirit chamber” in recognizing the worthiness of God. “Teach me Your way, O LORD; I will walk in Your truth; Unite my heart to fear Your name.” Psalm 86:11. Cf. Eph. 6:5; Col. 3:22; Matt. 22:37; Prov. 3:5; Deut. 11:13). This united heart will also promote peace and unity in Christian fellowship: “And let the peace of God rule in your hearts, to which also you were called in one body; and be thankful” (Col. 3:15).
Let us pray with David, “Let the words of my mouth and the meditation of my heart Be acceptable in Your sight, O LORD, my strength and my Redeemer” (Psalm 19:14).
Grace Notes: August 26, 2004. Copyright © 2004 by John Woodward. Permission is granted to reprint this article for non-commercial use. Scripture quotations (unless indicated otherwise) are from The Holy Bible, New King James Version © 1982 by Thomas Nelson, Inc.
 Dr. M. R. Dehaan, Heart Trouble, Our Daily Bread, May 10, 1996. rbc.org
 Jonathan Edwards, Religious Affections, part 1, chapter 2. Available online at www.CCEL.org. [1703-1758, pastor, educator, philosopher-theologian; a leader in the Great Awakening]
 The parts of man are identified in 1 Thess. 5:23: “Now may the God of peace Himself sanctify you completely; and may your whole spirit, soul, and body be preserved blameless at the coming of our Lord Jesus Christ.” For further study, see the online book at http://www.GraceNotebook.com/theological_papers_index.htm
For further study on the believer’s new heart, visit http://frankallnutt.com/NH.Home.htm (books) http://www.NewHeartExpressions.com (applied to addiction counseling) and See Grace Note: “Renewing Your Affections”