As the scale of the American Civil War became clear to Americans north and south, Protestant clerics engaged the subject of war more regularly in their preaching. By the Fall of 1861 the conflict’s first major battle—called variously First Manassas or First Bull Run—had been fought and surprisingly won by the upstart slaveholding Confederate republic with horrifying casualties. Ministers confronted war not as far off idea but as a reality experienced by parishioners, many of whom were parents or siblings (or both) of soldiers in the Confederate and Federal armies. Hugh Smith Carpenter, the pastor Westminster Presbyterian Church in the then-independent city of Brooklyn, New York, heeded President Lincoln’s wartime call for fast days and used one such fast day as an opportunity to preach a sermon on war.
Carpenter rejected theologies that “esteem the antagonism between these two things to be exclusive and final. The Gospel of God, and the bloodshed of battle, seem to them to confront one another, like angel and devil – like heaven and hell; -and to exchange no greetings whatever.” He also distanced himself from fellow divines who “invoke the God of battles with profane familiarity, and a flippant air, as if his judgment could be warped, and his favor challenged, by the splendor of an armament, the tramp of a march, or the momentum of a victory.” He had no time for ministers who claimed “the huzza of might as the benediction of the Almighty, and the triumph of a time, as the verdict of eternity.”
War still, however, had a place in the divine economy of the Christian life. War was certainly an evil, but it was a necessary evil. It was to be understood “as an agent for the control of other evils” and “a remedial measure.” In certain circumstances war becomes, “what poison is, when employed as a medicine in the human frame; what explosion is, when it destroys a building in order to arrest a conflagration; what temptation is, when it is suffered to try the human life in order to purify and invigorate the human heart.” War was analogous to “what prisons are, when they preserve the peace of the city, or what the death penalty is, when it secures life to society.” Like war, “all these things are, in themselves, contrary to the gospel, and to the golden rule. They will all be banished when Christ shall reign, Death himself shall die. The last enemy that shall be destroyed is death.” War, like all other evils, shall vanish with all the rest.” But in the meantime, Carpenter argued, “among these agencies, warfare has its place, its office.”
Warfare had a divine office, and therefore war and religion inevitably had some relationship to each other. “Religion touches war at two points; the one, as it is an infliction of the Divine Providence; and the other, as it is an appeal to the Divine Justice.” Carpenter declared that these ideas hallowed war and invested it “with sublimity”. That “such a sanctification is tremendous” was obvious, and where “religion sways war, there war becomes terrible with religious meaning.” War with religious meaning turned in to “the Mount Sinai of a present Providence, on which thunders threaten, and lightnings leap. Warfare, Carpenter announced, “is the reserve of Divine power; the opening of Divine possibilities.” 
 High Smith Carpenter, The Relations of Religion to the War, A Sermon Delivered on Fast-Day, Sept 26, 1861 (New York: W.A. Townsend, 1861), 3-5