The heart is a vital organ. "Heart" can also mean the emotional center of a person.
In Hebrew and Greek, as in modern English, "heart" refers to both a physical organ and the emotional center of a person. The Hebrew word lēb and the Greek word kardia are usually translated as “heart.”. Together they appear about 1,000 times in the Bible, although some translations use different words to express the meaning. These words have a wide range of meaning.
The Physical Heart
The beating of the heart is a sign of life. This idea appears in the story of Nabal, who was struck down and later died (1 Samuel 25:37–39). Food and wine can affect the heart by strengthening or gladdening it (Judges 19:5; Psalm 104:15; Acts 14:17). The Bible also speaks of the heart as able to “faint” or “tremble.” Because the heart is located at the center of the body, it became a natural picture for “the center” of something (Matthew 12:40).
The Psychological Heart
The Bible often uses the word heart to describe the center of human thought and decision-making. Some translations use the word mind when referring to this idea of the psychological heart. The heart can pay attention (for example, Jeremiah 12:11). The heart also:
perceives (John 12:40),
understands (1 Kings 3:9),
debates (Mark 2:6),
reflects (Luke 2:19),
remembers (Luke 2:51),
thinks (Deuteronomy 8:17),
imagines (Luke 1:51),
is wise (Ecclesiastes 1:17), and
has technical skill (Exodus 28:3).
The heart feels many emotions, such as:
intoxicated happiness (1 Samuel 25:36),
gladness (Isaiah 30:29),
joy (John 16:22),
sorrow (Nehemiah 2:2),
anguish (Romans 9:2),
bitterness (Proverbs 14:10),
anxiety (1 Samuel 4:13),
despair (Ecclesiastes 2:20),
trust (Psalms 112:7),
affection (2 Corinthians 7:3),
lust (Matthew 5:28),
callousness (Mark 3:5),
hatred (Leviticus 19:17),
jealousy (James 3:14),
desire (Romans 10:1),
discouragement (Numbers 32:9),
sympathy (Exodus 23:9),
anger (Deuteronomy 19:6), and
indecision (2 Chronicles 13:7).
The Bible also shows the heart as the center of a person’s will. The heart can:
plan or purpose (1 Corinthians 4:5),
lean or incline towards something (1 Samuel 14:7),
prompt a person to act (2 Kings 12:4; compare Proverbs 4:23),
remain steadfast and firm (Acts 11:23),
be eager and willing (Exodus 35:22),
follow its "treasure" (Matthew 6:21).
The Bible describes the morally good qualities that can come from the heart. The heart can be:
gentle and humble (Matthew 11:29),
holy (1 Thessalonians 3:13),
faithful (Nehemiah 9:8),
upright (Psalms 97:11),
pure, focused (James 4:8),
clean (Acts 15:8),
loving toward God (Mark 12:30),
loving toward others (1 Peter 1:22), and
hardened or sensitive (Ezekiel 11:19).
Scripture often stresses the evil that comes from the heart (Genesis 6:5 and throughout). The heart can be:
self-deceiving (James 1:26),
deceitful (Jeremiah 17:9),
greedy (Matthew 6:19–21),
lustful (Matthew 5:28),
arrogant or proud (Isaiah 9:9),
rebllious agaomst God (Acts 7:51),
perverse (Psalms 101:4), and
unwilling to repent (Romans 2:5).
Jesus taught that nothing makes a person more unclean than what comes from the human heart (Mark 7:18–19).
But the Bible also teaches that good can come from the heart (Luke 6:45; 8:15). Even when fear or circumstances prevent action, the intention of the heart still matters. A good intention is counted as good, and an evil intention is counted as evil (1 Kings 8:18; Matthew 5:28).
Because the heart is complex, it can become divided. Scripture praises a heart that is whole, perfect, and true—that is, a united heart (Genesis 20:5; Psalms 86:11; Acts 8:37). The word heart often refers to the total inner self, the hidden core of who a person is (1 Peter 3:4). With the heart a person communes with God, pouring out feelings in prayer, words, and deeds (Psalms 62:8; Matthew 15:18–19). The heart is the true self, different from appearance, public role, and physical presence (1 Samuel 16:7; 2 Corinthians 5:12; 1 Thessalonians 2:17). This inner self has its own nature, character, and disposition (translated as "mind" in Daniel 4:16; 7:4; see also Matthew 12:33–37).
The Spiritual Heart
The heart is especially important in biblical faith. The hidden self, which is a mystery to others, is fully known by God and by Christ (Jeremiah 17:10; Luke 9:47; Romans 8:27). The heart is where we understand God (2 Corinthians 4:6). The heart's condition affects how we see God (Matthew 5:8). We speak to God from the heart (Psalm 27:8). The heart is where God dwells within us (2 Corinthians 1:22; Galatians 4:6; Ephesians 3:17).
On the other hand, moral evil in the heart is understood in the Bible as sin against God. A heart without understanding becomes darkened, often hiding idolatry, and is far from God. Such a heart is “not right” before God (Deuteronomy 29:18–19; Matthew 15:8; Acts 8:21; Romans 1:21). Yet the Lord does not reject a heart that is broken and contrite (Psalms 51:17). When a person turns their heart toward God, God promises to make it sensitive to his ways, renewed, and purified (Deuteronomy 4:29; 2 Kings 23:25; Psalms 51:10; Joel 2:13; Ezekiel 36:25–27). God’s law is then written on the heart as an inward guide and motivation (Jeremiah 31:33; Hebrew 8:10; see also 2 Corinthians 3:2–3).
In Christian teaching, this transformation begins when a person believes the good news from an “honest and good heart.” Such a heart is like good soil that produces fruit when the word of God is planted in i (Luke 8:15; Romans 10:9). A true heart comes closer to God and loves God with all its mind, emotions, and will (Luke 10:27; Hebrews 10:22). God then gives strength, reward, renewal, grace, peace, and joy to the heart (Psalms 73:26; Isaiah 57:15; Acts 2:46; Philippians 4:7; Hebrews 13:9). In this way, the ancient ideal becomes possible again: to be a person after God’s own heart (1 Samuel 13:14; Acts 13:22).