It baffled the disciples to hear the Master say that evil, when viewed from a higher perspective, is good, that sin is a doorway to grace.
So he told them the story of Carthage, a thorn in the flesh of Ancient Rome. When Rome finally razed Carthage to the ground she found rest, grew flabby, and decayed.
“If all evil were to disappear,” concluded the Master, “the human spirit would rot.”
From More One Minute Nonsense by Anthony de Mello.