His law doesn’t change. The application of it does. Theologians wisely distinguish between natural law and positive law. This distinction, however, must be distinguished from natural law and revealed law. The latter distinction separates what we learn about God’s law from the created order, and what we learn from His Word. The former, however, distinguishes between the underlying, unchangeable principles, inherent in the nature of things, and the specific purposes of a particular law.
The most common example is the Old Testament requirement that one build a fence around one’s roof. Do we still have the requirement? Is the American church under a cloud of judgment for not obeying this law? By no means This is positive law. The natural law is broader- do not put your guests or visitors in danger. In Old Testament Israel the roofs of homes were places for social gatherings. In America that is generally not the case. The consistent law, the principle underlying the specific, the natural law may have as its application here, put a fence around your swimming pool so no one accidentally falls in a drowns. We still are required to pursue the safety of those on our property.
The ceremonial laws are much the same. God told the children of Israel to sacrifice lambs on Passover, so that they would remember God’s deliverance and look to the coming of the Lamb of God. When that Lamb came, the call to remember abides; the natural law does not change. The positive law now changes, such that we remember the once for all coming of the Lamb and His deliverance of us through the bread and the wine of the Lord’s Table.
Under the same heading, the kosher laws follow the same pattern. The positive law said, “Don’t eat the pork.” The natural law said, “Be a set apart and distinct people for Me.” In the new covenant the positive law finds its expression not in our diet, but in our love one for another. The borders of our commonwealth are determined by the faith once delivered, not a blood line that traces back to Abraham. We are still called to be a set apart people, but what sets us apart is what makes us a people, our dependence on the finished work of Christ.
The distinction between positive and natural law, of course, is not always easy to make. We are not free to simply dismiss the outward at will. Consider Nadad and Abihu who apparently thought positive law was this kind of fire and natural law was just fire. Things did not go well for them. One way we can know the difference, however, is when the Bible itself calls for the change. Jesus said the bread was His body broken, the wine the cup of the New Covenant. Jesus told Peter to eat the pork. This is the same Jesus who told us that not one jot or tittle would pass away from the law. Jesus is the same yesterday, today and tomorrow. His natural law reflects not only the nature of things, but His own unchanging nature. Circumstances may change. Our Lord does not. Neither then does our obligation to obey whatsoever He commands.