Never say that you can't do something, or that something seems impossible, or that something can't be done, no matter how discouraging or harrowing it may be; human beings are limited only by what we allow ourselves to be limited by: our own minds. We are each the masters of our own reality; when we become self-aware to this: absolutely anything in the world is possible. Master yourself, and become king of the world around you. Let no odds, chastisement, exile, doubt, fear, or ANY mental virii prevent you from accomplishing your dreams. Never be a victim of life; be it's conqueror.
To really change the world, we have to help people change the way they see things. Global betterment is a mental process, not one that requires huge sums of money or a high level of authority. Change has to be psychological. So if you want to see real change, stay persistent in educating humanity on how similar we all are than different. Don't only strive to be the change you want to see in the world, but also help all those around you see the world through commonalities of the heart so that they would want to change with you. This is how humanity will evolve to become better. This is how you can change the world. The language of the heart is mankind's main common language.