Grace is such an elastic term that it can mean so many different things, especially in te wider culture. At least for christians, i think it's important for us to anchor our definition of grace and our practice of grace in god's definition and practice of the cross. And there's two crucial dimensions to grace - we are getting active repair from god with the cost of that repair being borne overwhelmingly by god. Those two things have to be found in a christian, thoroughly christ centred definition of grace. The bible is actually clear that that understanding of grace should influence how christians participate in public discourse.