Passage
Surely thou wilt light my candle: the Lord my God wil lighten my darkenes.
Surely thou wilt light my candle: the Lord my God wil lighten my darkenes.
Psalms 18:26 With the pure thou wilt shewe thy selfe pure, and with the froward thou wilt shewe thy selfe froward.
Psalms 18:27 Thus thou wilt saue the poore people, and wilt cast downe the proude lookes.
Psalms 18:28 Surely thou wilt light my candle: the Lord my God wil lighten my darkenes.
Psalms 18:29 For by thee I haue broken through an hoste, and by my God I haue leaped ouer a wall.
Psalms 18:30 The way of God is vncorrupt: the worde of the Lord is tried in the fire: he is a shield to all that trust in him.
The verse centers on "light", "surely", "thou", "wilt", "candle", "lord", "lighten", and "darkenes". It is saying that the verse draws attention to "light" and "surely", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 27's "Thus thou wilt saue the poore people..." into verse 29's "For by thee I haue broken through...", so "light" and "surely" 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 "surely" with trust shaped by these words, not by a vague optimism outside the passage.