In this chapter we get to experience some of David’s wonderful poetry. This is a song of praise for God’s deliverance of David from his enemies, and is almost exactly like Psalm 18. Notice a couple thing. First of all, recognize the power and strength of God. He is described as a rock, fortress, and deliver in verse 2. His power is shown in verses 8-16, and His salvation, specifically for David but also for the rest of us, is shown in the rest of the chapter.
Second of all, notice David’s view of himself, he was about to die, maybe not literally but in a figurative way. All he held as true was being threatened, and he cried out the LORD. David speaks of his own righteousness in verses 21-24. Understand that this righteousness is not perfection or a lack of sin. But the Biblical understanding of true righteousness which comes by faith and not by works (Genesis 12, Ephesians 2, etc.) His being right with God is solely dependent upon his trust in God as the only One who can deliver him.
May we always be steadfast, trusting in God above all things: for our protection, for our deliverance, and especially for our salvation!