David Rothkopf: Christian nationalism is a us versus them construct. He says in Jesus, all of the dividing walls that we normally erect to define us versus them have been broken down by Christ. There's only an us; there's only one meaning for "us," he says. Rothkopff: We need to recapture a way to actually narrate and promote this definition of us,. That now is under so much assault, especially from movements like Christian nationalism.