Peace, War and the Devil

"In peace we can make many of them ignore good and evil entirely; in danger, the issue is forced upon them in a guise to which even we cannot blind them. There is here a cruel dilemma before us. If we promoted justice and charity among men, we should be playing directly into the Enemy's hands; but if we guide them to the opposite behaviour, this sooner or later produces (for He permits it to produce) a war or a revolution, and the undisguisable issue of cowardice or courage awakes thousands of men from moral stupor. This, indeed, is probably one of the Enemy's motives for creating a dangerous world—a world in which moral issues really come to the point. He sees as well as you do that courage is not simply one of the virtues, but the form of every virtue at the testing point, which means, at the point of highest reality."

—C.S. Lewis, The Screwtape Letters