pistis

Pistis (Greek: πίστις) is a Greek noun traditionally rendered as "faith," "trust," "belief," or "fidelity." It derives from the verb peithō, meaning to persuade or to trust, and its range of meanings covers both the reliability of a person or thing (fidelity, trustworthiness) and the assent or confidence placed in propositions, persons, or deities.

In classical Greek usage, pistis could denote trust in an individual, fidelity to an oath, or the assurance that something will occur. In philosophy, it functions as belief or assent to propositions and is often discussed alongside terms such as epistēmē (knowledge) and doxa (opinion).

In Jewish and Christian Greek literature, pistis acquires theological weight. In the Septuagint and the New Testament, pistis commonly translates Hebrew 'emunah' and conveys trust in God, belief in divine promises, and, within Christian writings, allegiance to Christ. The expression pistis Christou appears in various contexts, where it is rendered as faith in Christ or the faithfulness associated with Christ, depending on interpretation. The concept also encompasses ethical and communal dimensions—loyalty, fidelity, and confidence in God’s faithfulness.

In later religious literature, pistis also appears as a central term in Gnostic writings, including the text Pistis Sophia, where it names a key principle associated with faith. Across genres, pistis remains a core term for describing what it means to trust, believe, or remain faithful in relation to persons, propositions, and the divine.