Coward or Conqueror

Are you a coward or conqueror? Revelation 21:1-8 describes the New Jerusalem, where God dwells with his people, and there is no more death, mourning, crying, or pain. It’s a glorious promise of the world to come, but the passage says only “the one who conquers” will receive this heritage. Cowards will not. What must one do to be a conqueror?