This psalm is easy to understand. The psalmist speaks as a man who was close to death, who prayed to his god for healing, and who then survived whatever physical malady he had suffered.
The superstitious speaker believes that if he hadn’t cried out for mercy, he would have died; and he pledges to forevermore praise the supreme power — YHWH — that he thinks spared his life.
My question now is the flip side of that old coin toss of the gods — you know, our expectation of either reward or punishment for our behavior on earth. Has good and bad ever really mattered?
I’m sure that question sounds silly to fundamentalists who are counting on an afterlife in heaven. But my real question is, why then do good things happen to “bad” people who never, ever pray?