Mighty Be Our Theme

So, I think I've decided on a theme, I'm not really sure how how to put it though. Part of the theme would be persistence and courage, but also a lot of the book has to do with rising from the ashes, something like that. I'm just not sure how to describe the way Leymah Gbowee talks about this theme. It's kinda difficult to do because it's a memoir, someone's life...how do you give someone's life a theme??