Change the cruel hold religion has on people and nature. Expose the horrors and spirit-crushing nature of religions. Free the minds of humankind. Allow schools to teach real things. Stop churches getting rich off of lies and encourage people to be as faithful with their money toward real things that help people instead of making power-gluttons rich. I could go on.

Foundation beyond belief is a good example.

animals and other life are the ultimate none believers and they did just fine for hundreds of millions of years then humans come along with there beliefs that are seemingly so different to others beliefs its worth killing each other on mass. look at the state of the planet now we have been in charge for what? ill be generous, 3,000 years and look what we have done. the earth does not need humans at all, unlike bees or ants or trees. if I believed for some strange reason the logic in me would question the complete lack of evidence and make the most of this life anyway even if there was another.

I think many of us are already doing that just by being who we are.
Every day, in a million different ways, atheists are showing that one doesn't need
to be an adherent to religious dogma to care about the people around them and the
space that we all share. We show that we are not the stereotypical immoral, hateful,
baby-eaters, that we've often been portrayed as being. Many atheists are active within
their communities, doing worthwhile things to improve the lives of all sorts of people.
Non-belief is increasing among the populace, and the invisible sky-daddy hasn't brought
another flood to wipe us all out. We must be doing something right.
If you are looking for something that you can do, just find a cause that you believe in, and
get involved.

By knowing that most religions 'have blood on their hands'
Research, Christian Crusades, Egyptian, Greek, Roman, Neopagan and their numerous gods and goddesses. If you don't want to go that far back in time; ask living memories about certain 'religious' support of Nazis's, IRA, UVF and taliban/al qaeda; as to what they have done recently,in the name of their beliefs, books and/or gods.
The world is fine. However, some humans are not.

BY not judging people by their religious beliefs. I've found that most "spiritual" or agnostic people tend to take people at face-value, not based on whether you're a "good christian", who I've found to be hypocrites, pessimistic, and HIGHLY judgemental.