Citizens of the Kingdom of God are called to make the world a more just and kind place.  It is done by what we model.  This is the way of being salt and light.  “Listen to me, my people; hear me, my nation: The law will go out from me; my justice will become a light to the nations” Isa 51:4 (NIV).  When justice thrives, it gives light; when it wanes, darkness fills the nations (Isa 59:19).  Israel failed at being the light of the world.  Jesus came to revive it when He said to His followers, “You are the light of the world” (Mt 5:14).