A drop in the ocean, a change in the weather, I was praying that you and me might end up together, it's like wishing for rain as I stand in the desert, but I'm holding you closer than most cause you are my Heaven. ":O)
Moar C.S. Lewis! Prayer isn't an obligation in this case, and it serves not only God (presumably why we pray), but is also beneficial to the individual praying. Lewis recognizes both parties in the relationship and how important both God and human beings are in this dynamic.