The Purple Crown exhibits how Christianity's ultimate act of witnessing, martyrdom, is an inherently political act. York argues that the path of Christianity leads to a confrontation with the same powers that crucified Jesus.
Tripp York goes outside of the normal understandings of public theology and points to the most powerful persuaders within Christian history: the martyrs. The martyrs remind us of the moment in which all the world was simultaneously exposed as fallen and redeemed, of Christ's death and resurrection.
In York's telling, just as the martyrs' deaths reveals Christ, so too their lives bear witness to the City of God, exposing those powers and principalities that crucified Jesus and continue to crucify him through his followers. He includes the biography of the El Salvador priest Oscar Romero.