The way that we think of our hearts as an organ that pumps blood throughout our bodies is correct from a materialistic perspective, but the Bible has a different view of the heart’s primary function. The Hebrew word leb (labe) indicates that “the heart includes not only the motives, feelings, affections, and desires, but also the will, the aims, the principles, the thoughts, and the intellect of man. In fact, it embraces the whole inner man, the head never being regarded as the seat of intelligence. While it is the source of all action and the center of all thought and feeling the heart is also described as receptive to the influences both from the outer world and from God Himself.” In some instances, “Leb is used of the man himself, or his personality (Genesis 17:17)” and from a spiritual perspective, “the heart could be regarded as the seat of knowledge and wisdom and as a synonym of ‘mind’ when ‘heart’ appears with the verb ‘to know.’” The heart encompasses some of the activities that we typically associate with the brain. “Memory is the activity of the heart (Job 22:22),” but it goes beyond that and may even be “the seat of conscience and moral character.” The Bible tells us that “God controls the heart” and he is able to give us “a new one (Ezekiel 36:26).” The heart can also be thought of as a source of expression, it “stands for the inner being of man, the man himself, and is the fountain of all he does (Proverbs 4:4). All his thoughts, desires, words, and actions flow from deep within him. Yet a man cannot understand his own heart (Jeremiah 17:9)” (H3820).

The first appearance of the word leb in the Bible is in Genesis 6:5-6 where it says, “The LORD saw that the wickedness of man was great in the earth, and that every intention of the thoughts of his heart was only evil continually. And the LORD regretted that he had made man on the earth, and it grieved him to his heart.” In these verses we are told that God also has a heart and that it is the source or you might say the motivation for his spiritual activity. The Hebrew word that is translated intention in Genesis 6:5, yetser (yayˊ-tser) has to do with creation and is figuratively thought of as conception. Yetser is derived from the word yatsar (yaw-tsarˊ) which means “to mould into a form; especially as a potter; (figurative) to determine (i.e. form a resolution)” (H3335). A word that appears to be identical with yatsar means “to press (intransitive), i.e. be narrow; (figurative) be in distress” (H3334). The fact that the intention of the thoughts of men’s hearts was only evil continually after sin entered into the world indicates that the situation was hopeless. God wanted to give up on his creation (Genesis 6:6), but instead he started working out a way for people to be saved from the wickedness that is inherent in our fallen human nature.

The book of Job shows us that spiritual conflict is the result of Satan’s intervention in the lives of godly people. Although Job was described as “a blameless and upright man” (Job 1:8), God allowed Satan to afflict Job in order to prove that his devotion was sincere. During the process, Job’s friends tried to convince him that his wickedness was great and that he deserved to be punished (Job 22:1-11). Eliphaz the Temanite suggested to Job, “Agree with God, and be at peace; thereby good will come to you. Receive instruction from his mouth, and lay up his words in your heart” (Job 22:21-22). In his defense, Job stated:

“Behold, I go forward, but he is not there,
    and backward, but I do not perceive him;
on the left hand when he is working, I do not behold him;
    he turns to the right hand, but I do not see him.
But he knows the way that I take;
    when he has tried me, I shall come out as gold.
My foot has held fast to his steps;
    I have kept his way and have not turned aside.
I have not departed from the commandment of his lips;
    I have treasured the words of his mouth more than my portion of food.
But he is unchangeable, and who can turn him back?
    What he desires, that he does.
For he will complete what he appoints for me,
    and many such things are in his mind.
Therefore I am terrified at his presence;
    when I consider, I am in dread of him.
God has made my heart faint;
    the Almighty has terrified me;
yet I am not silenced because of the darkness,
    nor because thick darkness covers my face.” (Job 23:8-17)

Job thought that God had made his heart faint and that the Almighty had terrified him (Job 23:16), but in actuality, it was Satan that was responsible for the tragedies that Job experienced (Job 1:13-19, 2:7). Job knew that he needed to keep God’s commandments and also said that he had stored up God’s word as if it was necessary for his continued existence (Job 23:12), but the result Job got from his effort was not what he expected (Job 24:22-25).

Psalm 37 offers advice to those of us that feel God has abandoned or rejected us even though we have been doing the right things. It states:

Fret not yourself because of evildoers;
    be not envious of wrongdoers!
For they will soon fade like the grass
    and wither like the green herb.

Trust in the Lord, and do good;
    dwell in the land and befriend faithfulness.
Delight yourself in the Lord,
    and he will give you the desires of your heart. (Psalm 37:1-4)

Putting our trust in the Lord is a part of the process that we go through to be saved. The Greek word peitho (piˊ-tho) “in the active voice, signifies ‘to apply persuasion, to prevail upon or win over; to persuade,’ bringing about a change of mind by the influence of reason or moral considerations” (G3982). The Greek word pisteuo (pist-yooˊ-o) means “not just to believe, but also to be persuaded of; and hence, to place confidence in, to trust, and signifies, in this sense of the word, reliance upon, not mere credence, hence it is translated ‘commit unto’, ‘commit to one’s trust’, ‘be committed unto’” (G4100). “Peitho and pisteuo, ‘to trust,’ are closely related etymologically; the difference in meaning is that the former implies the obedience that is produced by the latter, cf. Hebrews 3:18-19, where the disobedience of the Israelites is said to be the evidence of their unbelief. Faith is of the heart, invisible to men; obedience is of the conduct and may be observed. When a man obeys God he gives the only possible evidence that in his heart he believes God” (G3982).

Proverbs 3:5-6 indicates that trust is an activity of the heart. Solomon instructed us to, “Trust in the LORD with all your heart, and do not lean on your own understanding. In all your ways acknowledge him, and he will make straight your paths.” The Hebrew word that is translated acknowledge, yada (yaw-dahˊ) has to do with knowing someone both relationally and experientially. One of the most important uses of the word yada is “depicting God’s knowledge of people: The Lord knows their hearts entirely (Exodus 33:12; 2 Samuel 7:20; Psalm 139:4; Jeremiah 17:9; Hosea 5:3)” (H3045). Jesus’ knowledge of the Pharisees hearts caused him to rebuke them on numerous occasions. In one instance, Jesus indicated that they had committed an unpardonable sin, blasphemy against the Holy Spirit (Matthew 12:32). Jesus asserted that the words we speak are an indicator of the condition of our hearts and said of the Pharisees, “You brood of vipers! How can you speak good, when you are evil? For out of the abundance of the heart the mouth speaks. The good person out of his good treasure brings forth good, and the evil person out of his evil treasure brings forth evil” (Matthew 12:34-35).

The book of Hebrews reveals that the Israelites never entered into the kind of relationship that God wanted to have with them because their hearts were hardened (Hebrews 3:8-9). The term that was used to describe the condition of the Israelites’ hearts was an “unbelieving” heart (Hebrews 3:12). The Greek word that is translated harden in Hebrews 3:8 is skleruno (sklay-rooˊ-no). “This word stresses that the nape of the neck stiffens and thus renders the head in an unbending position” (G4645). This condition of the heart is illustrated in the Old Testament by Pharaoh who persistently refused to obey the LORD’s command to let his people go. It says in Exodus 7:13 that Pharaoh’s “heart was hardened.” “In reference to Pharaoh, it means to brace up and strengthen and points to the hardihood with which he set himself to act in defiance against God and closed all avenues to his heart to those signs and wonders which Moses wrought” (H2388).

Moses’ summarization of the Israelites’ forty year journey included some sharp rebukes because of their unbelief. Moses said:

“At Taberah also, and at Massah and at Kibroth-hattaavah you provoked the Lord to wrath. And when the Lord sent you from Kadesh-barnea, saying, ‘Go up and take possession of the land that I have given you,’ then you rebelled against the commandment of the Lord your God and did not believe him or obey his voice. You have been rebellious against the Lord from the day that I knew you.” (Deuteronomy 9:22-24)

Moses said that the Israelites did not believe or obey the voice of God indicating that there was not only a lack of faith on their part, but also a lack of reverence toward God and yet, Moses interceded on their behalf and asked the LORD to give them a second chance. Moses prayed, “Do not regard the stubbornness of this people, or their wickedness or their sin, lest the land from which you brought us say, ‘Because the LORD was not able to bring them into the land that he promised them, and because he hated them, he has brought them out to put them to death in the wilderness’” (Deuteronomy 9:27-28).

The prophet Ezekiel’s message from the LORD indicated that the only way the problem of the Israelites’ hardened hearts could be fixed was to give them a new heart. The LORD told Ezekiel:

“Therefore say to the house of Israel, Thus says the Lord God: It is not for your sake, O house of Israel, that I am about to act, but for the sake of my holy name, which you have profaned among the nations to which you came. And I will vindicate the holiness of my great name, which has been profaned among the nations, and which you have profaned among them. And the nations will know that I am the Lord, declares the Lord God, when through you I vindicate my holiness before their eyes. I will take you from the nations and gather you from all the countries and bring you into your own land. I will sprinkle clean water on you, and you shall be clean from all your uncleannesses, and from all your idols I will cleanse you. And I will give you a new heart, and a new spirit I will put within you. And I will remove the heart of stone from your flesh and give you a heart of flesh. And I will put my Spirit within you, and cause you to walk in my statutes and be careful to obey my rules.^” (Ezekiel 36:22-27)

The LORD said that the Israelites’ heart of stone would be replaced with a heart of flesh (Ezekiel 36:26). The Hebrew word that is translated stone in this verse is the same word that is used in Deuteronomy 10:1 in reference to the tablets of stone that God wrote the Ten Commandments on.

Moses’ account of the Israelites’ journey shifted dramatically from a materialistic perspective to a spiritual perspective when he started talking about the second writing of the Ten Commandments. Moses stated, “At that time the Lord said to me, ‘Cut for yourself two tablets of stone like the first, and come up to me on the mountain and make an ark of wood. And I will write on the tablets the words that were on the first tablets that you broke, and you shall put them in the ark.’ So I made an ark of acacia wood, and cut two tablets of stone like the first, and went up the mountain with the two tablets in my hand. And he wrote on the tablets, in the same writing as before, the Ten Commandmentsthat the Lord had spoken to you on the mountain out of the midst of the fire on the day of the assembly. And the Lord gave them to me. Then I turned and came down from the mountain and put the tablets in the ark that I had made. And there they are, as the Lord commanded me” (Deuteronomy 10:1-5). Moses emphasized the fact that everything had been done just as it had been before and that God himself wrote on the tablets, “in the same writing” (Deuteronomy 10:4), meaning that it was God’s handwriting, signifying the legality of the documents. Moses went on to specify the terms of the contract that had just been ratified. Moses said:

“And now, Israel, what does the Lord your God require of you, but to fear the Lord your God, to walk in all his ways, to love him, to serve the Lord your God with all your heart and with all your soul, and to keep the commandments and statutes of the Lord, which I am commanding you today for your good?” (Deuteronomy 10:12-13)

Moses specified five things that the LORD required. First, the people were expected to fear or reverence the LORD, “whereby an individual recognizes the power and position of the individual revered and renders him proper respect” (H3372). Second, the people of Israel were expected to walk in all the ways of God, meaning that they were to exhibit a godly lifestyle, their behavior was supposed to be consistent with the God they served. Third, the Israelites were required to love God; they were expected to have a strong emotional attachment to him and have a desire to be in his presence. Fourth, the Israelites were required to serve the LORD with all their hearts and with all their souls. This meant that the people’s attention was to always be on the LORD and that he would be their number one priority in their daily lives. The final requirement that the people of Israel keep the commandments and statutes of the LORD was a matter of the greatest commandment (Deuteronomy 6:1-9) being evidenced in their lives. Everything that the Lord required of Israel really boiled down to whether or not the people would actually put their trust in God and believe that he was going to do what he promised to.

The stone tablets that the Ten Commandments were written on were likely meant to be representative of the Israelites’ hardened hearts. The Hebrew word that is translated tablets in Deuteronomy 10:1, luach (looˊ-akh) is used in Jeremiah 17:1 where it says, “The sin of Judah is written with a pen of iron; with a point of a diamond it is engraved on the tablet of their heart.” The concept of the heart being a tablet that can be engraved upon also appears in the New Testament in the Apostle Paul’s second letter to the Corinthians. Paul said, “And you show that you are a letter from Christ delivered by us, written not with ink but with the Spirit of the living God, not on tablets of stone but on tablets of human hearts” (2 Corinthians 3:3). Paul compared the Ten Commandments to a letter from Christ that was written with the Spirit of the living God, suggesting that it was possible to engrave the word of God on the human heart in the same way that God wrote the Ten Commandments on two stone tablets. The key to this process being successful might be what Moses described as the circumcision of the heart.

After Moses talked about the requirements of God’s relationship with the Israelites (Deuteronomy 10:12-13), he said, “Behold to the LORD your God belong heaven and the heaven of heavens, the earth with all that is in it. Yet the LORD set his heart in love on your fathers and chose their offspring after them, you above all peoples, as you are this day. Circumcise therefore the foreskin of your heart, and be no longer stubborn” (Deuteronomy 10:14-16). When Moses commanded the Israelites to circumcise their heart, he meant that they were to “remove the hardness and to love God” (H4135). This willful act was necessary to change the condition of the people’s hearts. Paul talked about the new life that believers are expected to live in his letter to the Ephesians. Paul instructed the Ephesians to “put off the old self” and to “put on the new self” (Ephesians 4:22-23). The Greek word that is translated put off, apotithemi (ap-ot-eethˊ-ay-mee) is derived from the word apo (apoˊ) which means “off” (G575) and tithemi (tithˊ-ay-mee) which means “to put” (G5087). Tithemi is associated with appointment to any form of service. “Christ used it of His followers.” From that standpoint circumcision of the heart or putting off the old self could mean that believers are expected to cut off any activity or relationship that interferes with their worship and/or service of God.

According to Paul, in addition to putting off the old self, it is necessary for believers to put on the new self in order for them to be able to trust in the LORD with all their hearts (Proverbs 3:5). It could be that Proverbs 3:3 is a prescription for doing just that. It states, “Let not steadfast love and faithfulness forsake you; bind them around your neck; write them on the tablet of your heart.” Steadfast love and faithfulness are two of the primary characteristics of God that are evident in his work of salvation. The Hebrew word that is translated steadfast love, cheçed (khehˊ-sed) “is one of the most important in the vocabulary of Old Testament theology and ethics…Checed implies personal involvement and commitment in a relationship beyond the rule of law…The Bible prominently uses the term chesed to summarize and characterize a life of sanctification within” (H2617). The Hebrew word ʾemeth (ehˊ-meth), which is translated faithfulness, means “stability” (H571) and is derived from the word ʾaman (aw-manˊ) which means to “believe.” (H539). Writing steadfast love and faithfulness on the tablet of our heart might mean that we commit to memory specific verses of the Bible that are relevant to these characteristics of God. At the end of his ministry, Jesus told his disciples:

“If anyone loves me, he will keep my word, and my Father will love him, and we will come to him and make our home with him. Whoever does not love me does not keep my words. And the word that you hear is not mine but the Father’s who sent me. These things I have spoken to you while I am still with you. But the Helper, the Holy Spirit, whom the Father will send in my name, he will teach you all things and bring to your remembrance all that I have said to you.” (John 14:23-26)

The Holy Spirit’s job is to help us understand God’s word and to remind us of the things that we’ve learned about Jesus, but he can only do that if we are committing scriptures to memory, i.e. writing them on the tablets of our heart.