The Weapon of Prayer by E.M. Bounds

Edward McKendree Bounds did not merely pray well that he might write well about prayer. He prayed because the needs of the world were upon him.

He prayed, for long years, upon subjects which the easy-going Christian rarely gives a thought, and for objects which men of less thought and faith are always ready to call impossible.

From his solitary prayer-vigils, year by year, there arose teaching equaled by few men in modern Christian history.

He wrote transcendently about prayer, because he was himself, transcendent in its practice. As breathing is a physical reality to us so prayer was a reality for Bounds. 

He took the command, 'Pray without ceasing almost as literally as animate nature takes the law of the reflex nervous system, which controls our breathing.