"Liberal" refers to people who believe that society can be changed for the better, and that government can be used as an instrument of such change. Because of their idealism, liberals often come off as unrealistic and sometimes downright flaky.
"Conservative" refers to people who have a much more "realistic" viewpoint: money rules; greed, not altruism, is what really drives human behavior; and human nature is so powerful that society can never be changed (except to strengthen the institutionalization of greed). There is a lot to be said for the accuracy of this viewpoint.
However, if we had not had millions of idealistic people working their buns off for the past several hundred years, each doing their tiny bit to make the world a better place, satisfied to make their incremental, almost-invisible changes which accumulated decade after decade, century after century, then we would still have slavery, public hangings, and open sewers running down the middle of our streets.
The forces of greed and corruption have become very powerful in recent years. I can only encourage idealistic people to keep struggling, to fight the inertia, to continue working to make the world a better place.