God alone is sovereign. This means (1) that there is no point in trying to appeal to other deities, and (2) that God is the God of the whole world. This means that when God’s covenant people become no different in their conduct from the nations of the world, they cease to be in any substantial way unique and are nothing more than just another “sinful kingdom.”
Christmas is, or at least it should be, a season of joy. But what is the joy of Christmas? Joy is the natural human response to the good news of Jesus. This joy is the inheritance of every Christian.