A couple of years ago during the winter, I was filling my gas tank in a less than pleasant section of Washington D.C. An African American man approached me to ask if I might have jumper cables. "Man," he said "my battery is dead from the cold. Everyone I ask says they don't have any cables. I'll give you $5 if you help me start my car." I hate to admit it, but my suspicion was aroused; the neighborhood, the man's appearance, the somewhat obvious setup. Having grown up in a monochromatic suburban area of Pennsylvania, I felt out of my element.
But something stopped me from merely replying with "no". It was the slight edge of desperation and loss of faith with fellow man in his voice that seemed genuine. The biting cold only made me empathize with the man further. While the chances of being robbed were probably equal to those of his battery being dead, I agreed. My parents were in the truck too and had little reason to understand why I was driving into a blind alley behind a derelict garage.
In the end however, the stranger was standing next to a beat up station wagon, hood lifted, with one very dead battery. As I connected the jumper cables and we got the car to turn over, he was generous with exclamations of gratitude. The man who had looked so shabby and down earlier was positively beaming. As I turned to leave, he thrust the promised $5 bill towards me. I politely declined and said, "That's okay, you don't have to pay me. Just help another stranger out when they need it and that's payment enough." The man looked initially confused, but then smiled and replied, "Thanks man. You know I think I am going to donate this to Haiti." I am fairly sure this guy could use the money himself, but he grasped the need to help other folks who just had their island devastated by an earthquake.
Do something good for another human being without expectation for anything in return. Ask them to do the same. It makes the world a better place.