Enlightenment is the Spirit’s work by which the gospel comes into clear intellectual view — a real understanding of the truth that is not yet saving surrender.
A person may be genuinely enlightened, grasping the meaning of the gospel and even tasting its goodness, without yielding himself to Christ. Hebrews speaks of those once enlightened who nevertheless fall away, and the parable of the sower shows the word truly received and yet choked or scorched.
Enlightenment must not be confused with drawing, conviction, or regeneration; understanding the gospel is not the same as being joined to Christ. It becomes saving only when the enlightened sinner surrenders in faith.
See in Scripture: Hebrews 6:4–6; 2 Corinthians 4:4–6; Luke 8:11–15; Ephesians 1:18