Many times when I read the Psalms, I tend to think of David as being overly dramatic. He is always talking about the cords of death, and how his enemies have surrounded him. Never having been faced with such circumstances myself, my brain tells me it is all exaggeration in order to plea his case before God. You might be tempted to do that within the opening lines of Psalm 3, but you would be wrong. David really did have thousands of people out to kill him this night, and one of them was his own son. (I encourage you to read the story in 2 Samuel 15-18 it will give you a good perspective on the psalm.)
Main Point: I am not so sure there is a “main point” that David was trying to teach, but I am sure that we should how we are to remind ourselves of the Lord’s faithfulness when all seems lost, and everything looks like it is stacked against us.
David spends very little time arguing the reasons God should answer his prayer, and more time focusing on why he could have confidence that he would be protected. He gave himself a metaphor that would be striking for a warrior, “A sheild that is all about him.” In a time where he needed to literally fear arrows coming for him, David must have taken great comfort knowing that there was more than armor bearers protecting him.
He also remembers what might seem to be a small event, but David rightly sees it as God’s hand upon him. David had gone to sleep the night before and woken up. Thats it! Thats all, but in that he could take great comfort. Of course for David it is a more heightened reality because he had assassins that were likely tracking him down, or possibly one of his close advisors might betray him in his sleep. But the point still remains that his lying and waking all happened because of the Lord’s sustenance (very specifically because the Lord thwarted the counsel of one his son’s advisors). The same is true for us.
Lastly, David could have confidence because his salvation did not depend upon him, but upon the Lord. The story bares this out when the writer of 2 Sam. tells us “All Israel” came out to fight David, and his mighty Men. David and his men routed them. A small group of fighting men killed 20,000 of the opposing soldiers that day. This was a miracle. The scriptures actually say that the forest of Ephraim killed more men than the sword.
So to it is with us. Our salvation, both in this life and in the one to come, is not wrought by our hands but by the hands of God.
Emotional Reactions: For me it brings a sense of peace in a world that is chaotic. It brings about a sense of something sure. He can be depended on, and we know that because he has already shown himself faithful in so much.