Those people are not real mourners who say, “Sure, the world’s in a mess, and I guess maybe I’m a bit guilty like everybody else, but what can I do about it?” What they’re really saying is that they are not concerned enough about themselves or the world to look for anything to do. No great burden hangs on their hearts. They aren’t grieved. They don’t mourn.

The kingdom citizen is different. Deep concern leads to definite action. So the mourners are really those who are concerned to the point of action.

from The Substance of Faith