καρδιογνώστης

a knower of the inner life

Definition

The Greek word καρδιογνώστης (kardiognōstēs) means 'knower of hearts' or 'one who knows the inner life.' It specifically refers to God's unique ability to perceive the deepest thoughts, motives, and character of a person, beyond outward appearances. In its two New Testament occurrences, it is used as a title for God, emphasizing His omniscience regarding human intentions. In Acts 1:24, the apostles pray to the Lord who knows the hearts of all, to show which man He has chosen. In Acts 15:8, God is described as the knower of hearts who bore witness to the Gentiles by giving them the Holy Spirit, just as He did to the Jews.

Biblical Usage

This word is used exclusively in the Book of Acts, both times in prayerful declarations about God's character. In Acts 1:24, it is used in the context of selecting a replacement for Judas, affirming that God alone can judge the inner fitness of the candidates. In Acts 15:8, it is used during the Jerusalem Council to argue that God, who knows the hearts of Gentiles, has accepted them by faith, evidenced by the gift of the Holy Spirit. The usage pattern shows it is a divine title applied in moments of significant decision-making within the early church.

Etymology

The word is a compound noun formed from καρδία (kardia, G2588), meaning 'heart' (the center of inner life), and γνώστης (gnōstēs), meaning 'a knower' or 'expert.' It literally means 'heart-knower.' The related verb γινώσκω (ginōskō) means 'to know' intimately. This construction highlights a deep, penetrating knowledge of the core of a person.

Semantic Range

This word is theologically significant as it underscores God's omniscience and His role as the ultimate judge of human character. It reinforces that salvation and divine approval are based on internal faith, which God alone perfectly perceives, not on external observance (as seen in Acts 15:8-9). Understanding this term enriches reading by highlighting that biblical prayer appeals to God's perfect knowledge of our true selves and His sovereign choice in matters of leadership and grace.

In the ancient Greco-Roman and Jewish world, the 'heart' (καρδία) was understood as the center of intellect, emotion, and will—the true self. The concept of a deity who knows hearts appears in the Old Testament (e.g., 1 Samuel 16:7, 1 Chronicles 28:9, Psalm 139). This title would resonate with both Jewish and Gentile audiences familiar with the idea of gods or an omniscient God who examines human motives, though the New Testament applies it exclusively to the God of Israel and the Father of Jesus Christ.

ἐπίγνωσις (epignōsis, G1922) — denotes full or precise knowledge, but is not a personal title for God. παντοκράτωρ (pantokratōr, G3841) — means 'Almighty' or 'Ruler of all,' emphasizing power rather than intimate knowledge.

Word Details

Scripture References