Saint Paul's epistle to the Galatians is an interesting one, particularly from the standpoint of Catholics who are trying to keep the Faith in spite of the Modernism which is today so prevalent. In the very first chapter, Paul speaks eloquently to the unchanging nature of the Faith:
He is saying that even the angels of heaven have no authority whatsoever to modify the truths of the Catholic Faith which have been revealed by God. And certainly no man has such authority.
In the second chapter of the same epistle, Saint Paul even goes so far as to reprove Saint Peter, the first Pope, appointed directly by our Lord Himself! Peter wasn't teaching a "new gospel," per se -- but he was just ignoring the problem of those who insisted that one must first become a Jew and observe the Mosaic Law, before one could become a Christian. You see, many of the early Christians were Jews, and they correctly understood Christ as the ultimate development of their former religion. But what they failed to understand was that Christ was more than a development -- He was a fulfillment -- and many things that no longer servedd their former purpose were to be left behind.
In today's reading, Paul is explaining that Christ is the fulfillment of a promise made by God to Abraham -- that one of His descendents would bring about the redemption of us all.2 He is reminding the Galatians (and us) that there was no Mosaic Law in the time of Abraham -- Paul is telling us that the Law was something given to man by God as a temporary expedient, until the arrival of the Redeemer.
But it is important to understand clearly what Paul is saying. The Mosaic Law contained two parts, and only one of them could be left behind. With the Redemption, the part of the Law which prescribed rituals and disciplines was to be discarded. There would no longer be animal sacrifices, now that we had the one perfect Sacrifice of the Cross and its renewal, in time and place, in the Sacrifice of the Mass. There would no longer be the circumcision of children; this purely outward sign of Judaism had been replaced with the inward and spiritual mark of Baptism. And there would no longer be prohibitions on what one could eat, or how many steps one could take on the Sabbath. There would be no strictures of ritual uncleanness, religious penalties for coming into contact with the dead, or with blood, or with lepers (like those mentioned in today's Gospel, who were required to have their cure certified by the Old Testament priests).
But the other part of the Law was unchanging -- that is the moral Law. In fact, the moral Law always existed -- even before Abraham. And it will always remain, unchanging, as long as their are people on this earth. It is what our Lord was speaking about when He said that He "came not to destroy the Law or the Prophets: I have come not to destroy but to fulfill."3 The moral Law, you see, exists in the unchanging mind of God. It is His immutable decree as to how He wants us to behave with respect to Him, and with respect to those around us. Indeed, His moral Law is largely something that we ought to be able to know without being told through divine revelation. It should be obvious to everyone that no society can last very long or be very prosperous if people are going about lying, killing, cheating, stealing, and beating one another. It should be obvious, as well, that mankind has a duty to honor its Creator and to keep holy His Name -- at least in a general way -- even to those who have not received the specific grace of the Catholic Faith, This is why the foolishness about removing the Ten Commandments from the courthouse in Alabama is so ridiculous -- the judges are trying to erase the most permanent thing in God's creation -- His eternal Law.
Many non-Christian societies have understood the need for embracing the natural moral Law. Even before Moses, we know that Hammurabi legislated a legal code in many ways similar to what we find in Exodus and Deuteronomy. We can find similar codes in the writings of the Moslems and Hindus and the other major religions of the world.
Christianity is rather unique in not attaching fixed penalties to specific violations of the moral Law. In many other societies, sinners are liable to the death penalty even if their crimes are not violent. It is not uncommon to find severe beating, mutilation, and even death for crimes like adultery, perversion, and theft. But the teachings of our Lord are more merciful, and such severe penalties are not required, unless society sees them as necessary to protect itself from dangerous criminal behavior. That is certainly something for those who want to strip our society of its original Christian character to consider -- Christianity will be replaced with something and that something is likely to be a lot nastier. They really don't want to be governed by the penalties of the Law of Moses, or the Code of Hammurabi, or the Sharia of Islam! Without Jesus Christ, human efforts to enforce the natural Law can get quite nasty.
But as Paul says, "the promise" has been "given to those who believe." We are "children of the promise," and at least for the moment we are living in a nominally Christian society. Having been freed from the ritual and disciplinary burdens of the Mosaic Law, it is our privilege to honor God's natural moral law even without fear of great earthly punishment. It is our opportunity to conform our wills to the will of God; to follow the moral Law not out of compulsion, but out of love of God and the promise of eternal life with Him in heaven.
So, even if an "angel from heaven" tries to tell you otherwise, remember that morality is as unchanging as God Himself. And remember too, that it is our privilege as "children of the promise" to know, love and serve God in this world -- we should want nothing else, for anything less is to throw away our own inheritance.