Lots of people have the desire to make the world a better place than it is today. I think it's one of the most human of desires- wanting to improve upon our own situation and the situation of others. It's not exceedingly difficult to do. To me the approach to this is pretty basic and easy.
If a person wants to advance society and make the world a better place, they should first do their fair share of work, then do some extra. Carry your own weight, then expend more effort on things like humanitarian outreach, science and art. The total of effort we all put forward as a culture has to be more than the bare minimum to keep us fed, sheltered and clothed. If as a whole a society is just breaking even meeting needs with some people not quite carrying their weight and others doing a little extra, then there aren't resources left over to devote to art, science, sport or humanitarian efforts. We won't advance as a culture if we just break even.
This seems pretty rudimentary to me. A culture cannot devote time and resources to science and art unless first their basic needs are met. If a society is populated with a bunch of mooching freeloaders, it's not going to advance culturally or scientifically. When a culture becomes accepting of able-bodied people who are not productive, it's going to have a negative impact in that culture's ability to advance beyond it's current state. In fact, it may even regress, moving back to a less civil or cultural state.
How does this apply today? Obviously we don't live in a village and have to tend animals, build huts and harvest crops in order to provide for our basic needs. In the US we've moved away from an agrarian society. In fact, many experts would suggest we are moving past an industrial society. Our parents may have worked in factories, but our children are less likely to. It takes less of our total time to provide for our basic needs now than at any point in history.
But it's still important to have a work ethic. It doesn't matter whether a person has to work 7 hours a day or 2 hours a day to meet their basic needs, they need to do at least that. They need to do it well. Then they need to do extra so they have resources left over to help others, support science and art.
Here's the cold truth- society pays more money for the jobs it values the most. We reward productivity and innovation in valued fields with money, prestige and influence. The money, prestige and influence we earn over what we use to meet our needs can then be channeled toward art, humanitarian efforts, education or scientific advancement.
These are the rules. It doesn't matter how much you care about the plight of children in Africa if you never advance your career past a barista. It doesn't matter how much you want to promote free health care if you haven't earned the political power to help put it in place. You won't have much effect on others if you are struggling to meet your own needs. In fact, you may end up being a draw on resources your society could be using on the truly needy. By taking advantage of social programs and bouncing around from low-paying job to low-paying job you are a drain on the resources society has to offer. The more a society thrives, the more money and resources we have to devote to social causes and scientific exploration.
My whole point here is- if a person wants to make a difference, make the world a better place or advance a culture, they should work towards a good job and kick ass at it. It doesn't matter what the field is, as those change over time. Find the jobs your culture values and do one of them well. Earn money, influence, power and prestige that you can use to positively contribute to humanitarian change, science and art. Caring about things and having a lot of desire isn't enough. If you really want to make a difference and make the world a better place, you have to first thrive yourself. Then you can positively contribute to advancing a culture.