Passage
For thou art my lamp O Lord: and thou, O Lord, wilt enlighten my darkness.
For thou art my lamp O Lord: and thou, O Lord, wilt enlighten my darkness.
2 Samuel 22:27 With the elect thou wilt be elect: and with the perverse thou wilt be perverted.
2 Samuel 22:28 And the poor people thou wilt save: and with thy eyes thou shalt humble the haughty.
2 Samuel 22:29 For thou art my lamp O Lord: and thou, O Lord, wilt enlighten my darkness.
2 Samuel 22:30 For in thee I will run girded: in my God I will leap over the wall.
2 Samuel 22:31 God, his way is immaculate, the word of the Lord is tried by fire: he is the shield of all that trust in him.
The verse centers on "light", "darkness", "thou", "lamp", "lord", "wilt", 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 28's "And the poor people thou wilt save..." into verse 30's "For in thee I will run girded...", so "light" and "darkness" 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 "darkness" with trust shaped by these words, not by a vague optimism outside the passage.