Semper Lux: "Heart" in the Old Testament

1. The first step in understanding what the term “heart” (‏לב or ‏ לבב) means in the OT is that, at its core, refers to the organ of a person’s internal life or reality.

Gen 17:17- “Then Abraham fell on his face and laughed, and said in his heart, ‘Will a child be born to a man one hundred years old? And will Sarah, who is ninety years old, bear a child?’”
Gen 24:45- “Before I had finished speaking in my heart, behold, Rebekah came out with her jar on her shoulder, and went down to the spring and drew, and I said to her, ‘Please let me drink.’”

This encompasses intellect, emotions and will. Out of 867 total occurrences, Beale notes that the term refers to intellectual activity 205 times, emotional activity 166 times and volitional activity 195 times.

Intellectual: 1 Kings 10:24 “All the earth was seeking the presence of Solomon, to hear his wisdom which God had put in his heart.”
Emotional: Gen 42:28- Then he said to his brothers, “My money has been returned, and behold, it is even in my sack.” And their hearts sank, and they turned trembling to one another, saying, “What is this that God has done to us?”. See also Is 30:29 “You will have songs as in the night when you keep the festival, And gladness of heart as when one marches to the sound of the flute, To go to the mountain of the LORD, to the Rock of Israel.”
Volitional: Is 32:4 “The mind (‏‏לבב) of the hasty will discern the truth, And the tongue of the stammerers will hasten to speak clearly.”

2. The OT is very clear that God is in control of the human heart in each of its dimensions (intellectual, emotional, volitional) to do with as He wills. This is clear in the Exodus account of the hardening of Pharaoh’s heart.

Ex 4:21 “The LORD said to Moses, ‘When you go back to Egypt see that you perform before Pharaoh all the wonders which I have put in your power; but I will harden his heart so that he will not let the people go.’”

The Exodus narrative details this prediction of what YHWH would do with Pharaoh followed by a consistent hardening of Pharaoh’s heart through each of the ten plagues.
God is not merely sovereign in when it comes to a judicial hardening; the OT also views Him as responsible for the heart having a right orientation to God:

Ezek 36:26 “Moreover, I will give you a new heart and put a new spirit within you; and I will remove the heart of stone from your flesh and give you a heart of flesh.”

While God is ultimately sovereign in determining the orientation of the heart, this is fully compatible with mankind being responsible before God for their thoughts, decisions and actions:

Deut 15:7 “If there is a poor man with you, one of your brothers, in any of your towns in your land which the LORD your God is giving you, you shall not harden your heart, nor close your hand from your poor brother”

3. The heart, in its intellectual, emotional and volitional dimensions, is the organ through which a person’s spiritual relationship with God is governed. It is this three-dimensional internal reality through which a person is oriented to God, either rightly or wrongly. An improper orientation to God has already been seen in the example of Pharaoh’s hard heart. Moses, in several places, exhorts Israel to be rightly related to God with reference to the heart:

Deut 6:5-6 “You shall love the LORD your God with all your heart and with all your soul and with all your might. These words, which I am commanding you today, shall be on your heart.”
Deut 8:2 “You shall remember all the way which the LORD your God has led you in the wilderness these forty years, that He might humble you, testing you, to know what was in your heart, whether you would keep His commandments or not.”

As it applies to one’s relationship with God, the heart is to be totally and completely devoted to God. The Psalmist prays that His heart would be undivided in love for God:

Ps 86:11-12 “Teach me Your way, O LORD; I will walk in Your truth; Unite my heart to fear Your name. I will give thanks to You, O Lord my God, with all my heart, And will glorify Your name forever.”

The wholeness of heart and right relationship with God that is an internal reality in the heart is expected to spill out in outward obedience to God as is seen in David’s prayer to God on behalf of Solomon:

1 Chr 29:19 “and give to my son Solomon a perfect heart to keep Your commandments, Your testimonies and Your statutes, and to do them all, and to build the temple, for which I have made provision.”

However, it was precisely a division of heart or lack of “wholeness” of heart that lead to Solomon’s spiritual downfall:

1 Kgs 11:4 “For when Solomon was old, his wives turned his heart away after other gods; and his heart was not wholly devoted to the LORD his God, as the heart of David his father had been.”

However, God foretells a time when He would, through the Spirit, orient His whole people’s hearts to Himself properly with the corresponding outworking of covenantal obedience:

Jer 31:33 “But this is the covenant which I will make with the house of Israel after those days,” declares the LORD, “I will put My law within them and on their heart I will write it; and I will be their God, and they shall be My people.”

4. If 1-3 above are true, then it follows Biblically that when God acts to bring a person into right relationship with Himself by acting internally on their heart, it has a corresponding result that transforms a person intellectually, emotionally and volitionally. The prophecy in Ezekiel 36 that God would give His people a new heart of flesh indicates spiritual transformation. If the heart consists of an intellectual, emotional and volitional component then it follows that all three will be renewed when God acts to give people a new heart. Those who have been spiritually transformed and given a new heart should think about the world and their life differently. Their emotions will be correspondingly affected so that they will respond to God with the proper emotional response. In addition, it should affect the way a person lives their lives and the decisions that they make.
When these three dimensions are combined, it results in an internal life that is wholly committed to God and the cause of His glory and kingdom on the Earth. Because we are whole beings and not merely a body a soul loosely united, the transformation of a person’s internal reality will result in a life that manifests outward obedience to God that is properly motivated by the heart.