Is the natural law enough? The natural law is, in many ways, synonymous with the moral law, however the moral law is far broader and deeper than what the natural law tells us.
The natural law includes the 1st and 2nd commandments. Paul’s letter to the Romans tells us that all men know something about God’s existence, and His nature. His finger prints are all over his creation, and those finger prints point us back to His glory. Religion is a universal reality… a global phenomenon. Men long to know God and they seek for Him even as they try to hide themselves from Him. They grope in the darkness toward Him even as they love the darkness and hate the light. We sons of Adam are a schizophrenic lot!
The problem is this: what can be known about God from nature does give the clarity to see that the true God is the Triune God that has revealed Himself in Jesus Christ. All to common, therefore, has been the earthly rule of the idolatrous theocracy…. that monstrous union of cult and culture referred by the Apostle John in his Revelation as the Beast. John knew the terror of the Beast for he was an eyewitness of the beastly power of the Roman Empire. The Caesars had proclaimed, “there is no other name by which you can be saved.” Powerful emperors claimed to be the incarnation of deity, just as the Pharaohs of Egypt and the mighty kings of the Ancient Near East had done. The pages of history are filled with tyrants who longed to be exercise the power of gods upon the earth.
But the rock of Christ smashes all such pretensions. He humbles empires and rebukes kings, reminding them that He alone is God incarnate. The name of Christ, and not the name of Caesar, is the only name under heaven by which we might be saved. And He reminds us, that as His Kingdom is not of this world, the affairs of this age which is passing away can never be of ultimate importance. All the great political questions will pass away and come to nothing.
So, what is the point? My point is simple. For the Christian, natural law provides a firm foundation to build common ground as we work together to the realm of politics. Nevertheless, the natural law is not enough. It is not a firm enough foundation upon which to build a political system with the humility to affirm that politics itself is not ultimate, that the State is not a god, and that higher King claim our highest allegiance. We need Christ to accomplish all that, and therefore it is not at all surprising that Christianity gave birth to separation of Church and State.