[I don't remember when I first heard the following story (I want to think it was related about or by D. L. Moody), but I've always liked it. I relate it as I remember it, which may not be exactly how I heard it. If anyone knows the origin of the story, I'd be glad to know. Thanks.]
An old preacher traveling by train was trying to sleep, but a young man had a baby with him that was constantly crying. The preacher said to the father, "Why don't you get that baby to shut up. Take it to its mother!" The man with the baby replied, "I would, but she's in a casket in the cargo car. We are going home to bury her." The preacher was struck with his own selfishness and insensitivity, however unintended. He sat down and said, "I've raised several kids; let me take the baby." And as the tired father fell asleep, the preacher walked the baby up and down the car and sang lullabies.
Don't criticize until you see the big picture -- know the whole story. Things are not always what they appear to be. (We often never know the whole story, so perhaps we should generally crucify the critical spirit).