A hundred years ago the question would have been easy and everyone would have answered with "God." and with that have a good motivation and moral compass. These days it is not so simple for most people. I used to live for the good of the world, then for dead people, and most recently for myself. However living for myself is not good enough, because it makes me very vulnerable to seeking pleasure in the moment, saying "Fuck it all", and the like. So out of curiosity and possibly for inspiration - What do you live for?