Passage
For thou wilt light my candle: the LORD my God will enlighten my darkness.
For thou wilt light my candle: the LORD my God will enlighten my darkness.
Psalms 18:26 With the pure thou wilt shew thyself pure; and with the froward thou wilt shew thyself froward.
Psalms 18:27 For thou wilt save the afflicted people; but wilt bring down high looks.
Psalms 18:28 For thou wilt light my candle: the LORD my God will enlighten my darkness.
Psalms 18:29 For by thee I have run through a troop; and by my God have I leaped over a wall.
Psalms 18:30 As for God, his way is perfect: the word of the LORD is tried: he is a buckler to all those that trust in him.
The verse centers on "light", "darkness", "thou", "wilt", "candle", "lord", and "enlighten". It is saying that the contrast between light and darkness marks a real divide in how people respond to God's work.
The nearby context moves from verse 27's "For thou wilt save the afflicted people..." into verse 29's "For by thee I have run through...", so "light" and "darkness" belong inside that flow. In Psalms context, the local focus is worship, trust, the LORD's kingship, and covenant mercy.
A plain takeaway is to answer the verse's own emphasis on "light" and "darkness" with trust shaped by these words, not by a vague optimism outside the passage.