φῶς

The Greek word phos has a broad semantic range, encompassing physical light, such as the sun, stars, or a lamp, as well as figurative light that illuminates understanding or spiritual truth. In the New Testament, phos frequently describes divine revelation and God’s righteous character. It portrays both God himself as the source of all light, and also his truth as that which dispels spiritual ignorance and error. This concept is often contrasted with darkness, which symbolizes sin, spiritual blindness, and evil. The term also carries significant theological weight, as it is intimately connected with life and salvation. To walk in the light is to live in fellowship with God and to abide in his truth and moral purity, while to walk in darkness signifies a life alienated from God and characterized by sin. The concept of light in the New Testament builds upon Old Testament themes where light often represented God’s presence, guidance, and favor (e.g., Psalm 27:1). A key theological development in the New Testament is the personal identification of Jesus Christ as the "Light of the World," who brings spiritual illumination and salvation to humanity. Believers are also called to be "light in the Lord," reflecting God's character and truth to the world through their good deeds.