Passage
Surely thou art my light, O Lord: and the Lord will lighten my darkenes.
Surely thou art my light, O Lord: and the Lord will lighten my darkenes.
2 Samuel 22:27 With the pure thou wilt shewe thy selfe pure, and with the frowarde thou wilt shew thy selfe frowarde.
2 Samuel 22:28 Thus thou wilt saue the poore people: but thine eyes are vpon the hautie to humble them.
2 Samuel 22:29 Surely thou art my light, O Lord: and the Lord will lighten my darkenes.
2 Samuel 22:30 For by thee haue I broken through an hoste, and by my God haue I leaped ouer a wall.
2 Samuel 22:31 The way of God is vncorrupt: the word of the Lord is tryed in the fire: he is a shield to all that trust in him.
The verse centers on "light", "surely", "thou", "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 28's "Thus thou wilt saue the poore people..." into verse 30's "For by thee haue I broken through...", so "light" and "surely" belong inside that flow. In 2 Samuel context, the local focus is covenant, worship, and faithfulness.
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.