What does the Bible say about illumination and conversion?

Illumination is described in scripture as a miraculous work of divine grace where God sheds light on the darkened heart of sinners. Hebrews 10:32 emphasizes the significance of remembering the time when believers were illuminated, which refers to the moment they recognized their sinfulness and the need for Christ. This illumination is not something initiated by the sinner but is purely an act of God's grace, a demonstration of His sovereignty in salvation. The Apostle Paul’s experience on the Damascus Road serves as a vivid illustration of this transformative event, as he went from persecutor to proclaimer of the Gospel after being illuminated by the light of Christ.

This act not only reveals one's own sinfulness but simultaneously enlightens them to the beauty and necessity of the Savior. Peter writes in 2 Peter 1:19, that we have a more sure word of prophecy that shines as a light in a dark place. Therefore, illumination is central to the Reformed understanding of regeneration and conversion, where the sinner is shown both their state before God and the wonderful remedy found in Christ alone, aligning with the doctrine of sovereign grace.