'Heart' in the Bible

Take care, brothers and sisters, that there not be in any one of you a wicked, unbelieving heart [which refuses to trust and rely on the Lord, a heart] that turns away from the living God.

For the word of God is living and active and full of power [making it operative, energizing, and effective]. It is sharper than any two-edged sword, penetrating as far as the division of the soul and spirit [the completeness of a person], and of both joints and marrow [the deepest parts of our nature], exposing and judging the very thoughts and intentions of the heart.

Just consider and meditate on Him who endured from sinners such bitter hostility against Himself [consider it all in comparison with your trials], so that you will not grow weary and lose heart.

For the Lord disciplines and corrects those whom He loves,And He punishes every son whom He receives and welcomes [to His heart].”

Do not be carried away by diverse and strange teachings; for it is good for the heart to be established and strengthened by grace and not by foods [rules of diet and ritualistic meals], which bring no benefit or spiritual growth to those who observe them.