I Corinthians 10:13 (KJV) "There hath no temptation taken you but such as is common to man: but God is faithful, who will not suffer you to be tempted above that ye are able; but will with the temptation also make a way to escape, that ye may be able to bear it"
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