She knew from a young age that her sole 'purpose' (in life) was to be a writer. [=she knew that all she wanted (in life) was to be a writer]
We were happy to know that the money was being used 'for a good purpose'. [=for something useful, important, etc.]
There's little/no 'purpose' in restarting the process. [=there is little/no reason to start the process again]
(..) I don't know. So what's the point of serving a god, none of us knows what he wants? I think about that all the time. I don't think it's our purpose to understand. Except one thing. We're soldiers. We have to know what we're fighting for. I'm not fighting so some man or woman I barely (..)2017 TvShow: Game of Thrones Title: Beyond the Wall Season: 7 Episode 6