One man challenged another to an all-day wood chopping contest.
The challenger worked with all his might, stopping only for a brief lunch break. The other man had a leisurely lunch and took several breaks throughout the day. At the end of the day, the challenger was surprised and somewhat annoyed to find that the other fellow had chopped substantially more wood than he had.
"I don’t get it," he said. "Every time I checked, you were taking a rest, yet you chopped more wood than I did. How did you do it."
"Didn’t you notice," said the winning woodsman, "that I was sharpening my ax when I sat down to rest."
Prayer is the action of sharpening the ax.