Saving the world is something that is going to be a lifelong concern for all of us, but this is true for lawyers, bakers, bus drivers, school teachers, ballet dancers, and horticulturalists. Saving the world isn’t a specialty to which one can “devote one’s life.”
I think you’ll see what I mean if you consider my own case. I’m a writer, and writing is what I devote my life to. Even if all my writing were directed to the end of saving the world, however, I wouldn’t say I was devoting my life to saving the world.
Like every other living thing on this planet, you have to make a living. This is true of every single living creature here. You might say that the Yanomami Indians of Brazil are leading harmless lives, but they don’t make their living by saving the world.
In other words, “saving the world” is not a profession—you can’t make your living by doing it. The way you have to see it is that everyone (as they make their living) must be aware of the necessity of saving the world. No one is exempt. At the same time, some people’s way of making a living can have more impact on this than others.
You must ultimately find the place where you can be most effective, and this will inevitably be in doing what you’re best at. In other words, no one is “good at” saving the world; one is good at music or painting or writing or politics or science—and any of these can put one in a position to make a contribution toward saving the world. But there is also no occupation that debars one from making a contribution toward saving the world.