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]
(..) Ok, what about the wounds on her arms? I pulled some thorns out. Looks like she ran into a thorn bush out there. She probably did it on purpose. What? David... From now on, she is gonna do whatever it takes to get out of here. Mia. (..)2013 Evil Dead