The Romans had mastered the art of talking about peace while waging the almost constant war, always — of course — in the interest of preserving their pax. They littered the landscape with temples to peace and inscriptions about peace at the same moment their regiments were crushing rebellions and slashing their way to more and more conquests. But the peace that Rabbi Jesus was talking about and demonstrating was shalom, not pax. It was not the peace that was brutally enforced in the emperor's name; it was the peace that is a gift of God. It did not come from the top down, but from the bottom up. It was not a peace marked by the jittery comfort of the gentry and a resentful passivity of those that were dispossessed. It was the shalom of which the prophets had sung, in which every man would sit under his own fig tree and there would be no more poor in the land. It was peace among persons, between peoples, and between humankind and the natural world.
There can be little doubt that this is a demanding vision. No wonder interpreters for centuries have found ways to dismiss it. One device, favored by Martin Luther, among others, was to teach that the Sermon on the Mount described how Christians should act in their personal relations with their families and friends and neighbors. But, the great Reformer insisted, to try and apply it to the public realm was to defy the structures God had ordained to impose order on civic life. It was to undercut the responsibility of the magistrate who was not only permitted but was also commanded to wield the sword when necessary. The classic Catholic response was that those in "religious life" should be guided by these teachings, but they were not applicable to governance and certainly not to making war when war was called for. But despite all the efforts to shrink the scope of their application, the Beatitudes (and the woes) continue to nurture the troubled consciences of millions of people.— Harvey Cox, When Jesus Came to Harvard