I think this saying is pretty much saying that what you put out you will get back in the world. If you wish to see the world be a better place then do what you can to make it a better place. By doing this you will not only improve other peoples perspectives of the world but also of yourself too. While people believe Gandhi has said, Be the change you wish to see in the world, these words have been paraphrased from a couple sentences that was published back in 1913.
We but mirror the world. All the tendencies present in the outer world are to be found in the world of our body. If we could change ourselves, the tendencies in the world would also change. As a man changes his own nature, so does the attitude of the world change towards him. This is the divine mystery supreme. A wonderful thing it is and the source of our happiness. We need not wait to see what others do. - Mohandas Gandhi
If you were to change to be a better person then the attitude of the world would also change towards you. Although he does not specify that the world's attitude would change for the better I would like to believe it would. For instance I really enjoy playing pool. I am always saying I will get better, I will improve and I want others to improve as a sort of mantra. In my mind then the world would recognize that I want to be always improving, although it is very possible that the world would change towards me and say that I will always need improvement. Just with any sport though when you think you are the best then you should quite because you will never get any better, but that should be another blog topic.
Even though Gandhi didn't say these exact words I feel that it is close enough to the message he was trying to get across that a lot of people incorrectly attribute it to him. Why not try to make the world a better place either way though. So pick up a piece of trash and maybe the world will clean something up for you. Be generous to people who deserve your help and when you deserve the help then maybe the world will step up. Find that thing that you can improve, take a leap of faith, and make a change.