"Every action of our lives touches on some chord that will vibrate in eternity." - Edwin Hubbel ChapinUsed to be the phrase I often heard was "nothing matters". No matter what you do, you are not going to be able to change anything. The powers that be hold all the cards, and you, being a peon, are screwed regardless.
Recently I have occasionally heard the phrase "everything matters", the idea being every little action you take has some effect, and if many people take tiny positive actions the cumulative effect with be that things will get better all around.
The powers that be can still make things miserable for large numbers of people, but they can't squash everyone, and they won't live forever. So a positive attitude from the majority can influence the outcome.