What does James 5:18 mean?
This verse concludes James's thought which he began in the previous verse. James has been using the example of Elijah's prayer. Elijah was, ultimately, just a mortal man. And yet, his prayer was powerful and effective. Prayer works, but not because of the power of the one who prays. It works because God hears, and responds with all of His power and effectiveness.The event James references is found in the book of 1 Kings, chapters 17 and 18. God stopped and started the rain in highly dramatic fashion in response to Elijah's obedient prayers. The story is definitely worth reading.
James's larger point is that people who trust God, pray in response to all of life's circumstances. We pray for ourselves. We pray for each other. We pray for healing. We pray for others to overcome their sin. God receives all of those prayers and responds to them in love and out of His great power and goodness.