There is a basic Torah teaching, middah k'neged middah. It means, "What goes around comes around." It is learned from Hillell when he saw a skull floating on top of the water. He said (to it): "Since you drowned [others, others] drowned you. And in the end, those that drowned you will be drowned."

     Not only do negative Deeds bring about more negative deeds, but certainly good deeds bring about more good deeds. This is an added reason for doing something good. Not only did you please Hashem when you did that first good deed, but doing it will bring you the opportunity to do another good deed. 

     Do something good today and see if you can recognize what further good opportunity it brought to you… and that will bring you another good opportunity....