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]
(..) It would have been a lot tougher if I would have had to make it on my own. When I wake up in the morning and I look over and I see my wife, that gives me the sense of purpose. It's not all about the money. Money can keep you warm. It pays your heating bills, you know. It can buy you a blanket. (..)2009 Up in the Air
(..) -You've got to love them. -That's racist. I'm like my mother. I stereotype. It's faster. Are you mad at your computer? I type with purpose. What is it that you're working on so furiously? I'm building a workflow of firing techniques. It's questions and responses, (..)2009 Up in the Air