καρδία

In ancient Greek thought, and particularly in the biblical context, *kardia* (heart) is not primarily understood as a physical organ for pumping blood, but rather as the core of human existence. It represents the very seat of one's being, the wellspring from which intentions, desires, and decisions emerge. It is the spiritual and moral center, distinct from but related to the mind (nous) and spirit (pneuma).

This broad semantic range means *kardia* can refer to intellectual activity, such as understanding and reasoning, as seen in passages that speak of the heart as the place where God writes his laws or where one settles a matter. It also denotes the emotional life, encompassing feelings like joy, sorrow, and love. Most significantly, it touches upon the volitional aspect—the will and moral choices a person makes. Therefore, actions and words are often portrayed as direct outflows from the condition of the heart.

Biblical usage frequently highlights the heart as the locus of faith and commitment to God. A pure heart is one devoted to God, while a hardened heart resists divine truth. God is depicted as searching the heart, emphasizing its ultimate significance for judgment and relationship. The New Testament connects a renewed heart with the work of the Holy Spirit, transforming an individual from within.