PURE RELIGION To Care for Widows, Orphans, and Strangers: The biblical ethical starting-point

Could there be a common theme or ethical principle found consistently throughout the Bible exposing the very “starting-point” and "original position" of all social ethics? This Biblical-ethical "theme" is the paramount concern and care for "widows, orphans, and strangers." As James, the brother of Jesus, writes, “Religion that is pure and undefiled before God, the Father, is this: to care for orphans and widows in their distress, and to keep oneself unstained by the world” James 1.27.