Religion in the American Civil War: How Both Sides Used the Same Bible to Justify War

In a Lex Fridman podcast episode, renowned historian Gary Gallagher delves into a frequently overlooked yet crucial dimension of the American Civil War (1861-1865) — religion. In this bloody conflict that tore America apart, both sides were predominantly Protestant Christians, and the Christian faith not only profoundly shaped the spiritual world of soldiers but was simultaneously invoked by both warring parties to justify the legitimacy of their cause.

The Civil War Era: A Deeply Devout American Society

According to Gallagher, Civil War-era America was a society permeated by an intensely religious atmosphere. Both warring sides — whether the Northern Union or the Southern Confederacy — were predominantly Protestant Christians, and religious sentiment ran extremely strong within the armies.

This deeply devout social atmosphere had profound historical roots. Mid-19th century America was still riding the afterwaves of the Second Great Awakening. This religious revival movement, which began in the 1790s and continued through the 1840s, deeply implanted Methodist, Baptist, and Presbyterian faiths into every corner of American society through open-air revivals and itinerant preachers. By the time the Civil War broke out, church membership had grown several times over compared to the Revolutionary War period, with religious participation reaching unprecedented levels. It was precisely on this religious soil that both sides could so naturally mobilize faith as a spiritual resource for war.

The military structure widely included chaplains, and for units with Catholic majorities, Catholic priests accompanied the troops as well. The chaplain system in the American military dates back to the Revolutionary War and was quite mature by the Civil War. In 1861, Congress legislated that each regimental unit could have one chaplain, elected by vote of the regiment's officers. It is estimated that approximately 3,000 chaplains served in the Union army throughout the Civil War; though Confederate records are less complete, chaplains were similarly widespread. Their duties included not only conducting worship services and preaching but also comforting the wounded, praying for the dying, and helping write letters home. This meant that faith was not a private matter but was systematically embedded within military organization. For soldiers teetering between life and death, religion became a crucial source of spiritual support.

This deep religious soil set the stage for how both sides would later use faith to explain and justify the war. When the vast majority of a society identifies as Christian, religious discourse naturally becomes a powerful tool for mobilizing, inspiring, and rationalizing war.

One Bible, Diametrically Opposed Positions

When asked whether Christianity was used to justify the war, Gallagher's answer was unequivocal: "Of course, both sides were using it." This is the most tension-filled paradox in Civil War religious history — the same Bible, the same God, simultaneously invoked by opposing sides to support diametrically opposed positions.

Gallagher points to a thought-provoking fact: the Bible itself is filled with accounts of battle and killing. "There's a lot of fighting in the Bible, a lot of people killing other people." This provided a textual foundation for sacralizing violence — as long as killing was done "for just cause," it could be explained within the framework of faith.

This interpretive flexibility is precisely the key to how religion gets exploited for political and military purposes. Specifically, Southern ministers and theologians developed an elaborate biblical argument system to defend slavery: they cited the story in Genesis of Noah cursing Ham's descendants to servitude, Leviticus's laws regarding the purchase of servants, and the Apostle Paul's return of a runaway slave to his master in the Epistle to Philemon. Southern theologians like James Henley Thornwell and Robert Lewis Dabney emphasized "literal interpretation," arguing that the Bible never explicitly condemned slavery itself. Northern abolitionists, meanwhile, emphasized the Bible's "spiritual principles" — such as "love your neighbor as yourself" and the equality of all people before God — arguing that these principles necessarily pointed toward the abolition of slavery. This fundamental divergence in hermeneutical methodology is the deeper reason why the same Bible produced diametrically opposed conclusions.

The same theological discourse could serve the North's mission of "preserving the Union and emancipating the enslaved" as well as the South's cause of "defending the homeland and maintaining the existing order." Faith here was no longer a moral arbiter but became a brief for whatever argument one wished to make.

"God Is Testing Us": How Faith Helped Digest Military Defeat

Another important function of religion in the war was helping people endure setbacks and defeat. Gallagher describes a typical psychological mechanism: when the military situation turned unfavorable, people would say, "This is God testing us."

So what do you do when God is testing you? Gallagher's summary is incisive and powerful: "When God is testing you, you don't give up; when God is testing you, you try harder."

This "testing narrative" possesses tremendous psychological resilience, with roots traceable to the deeper American tradition of Providentialism. Since Puritan times, Americans have tended to view themselves as God's chosen people and America as a "city upon a hill." This worldview holds that everything in the course of history — whether prosperity or adversity — is a manifestation of God's will. Within this framework, military defeat is not evidence of God's abandonment but rather proof that God is still watching over and shaping this nation. This mode of thinking has deep roots in the Judeo-Christian tradition, continuous with the Old Testament narrative of the Israelites repeatedly suffering yet remaining God's chosen people.

It reframed military setbacks as trials of faith, thereby transforming defeat into motivation to persevere. For a war lasting four years with horrific casualties, this spiritual mechanism was crucial for maintaining morale and preventing collapse. It explains why both sides could continue fighting in the face of enormous losses — every defeat was imbued with transcendent meaning.

Why Southern Generals Were More Devout Than Their Northern Counterparts

Gallagher raises a particularly interesting historical observation: the most famous high-ranking generals on the Confederate side displayed notably greater religious devotion than those on the Union side.

The South's legendary generals — Robert E. Lee, Stonewall Jackson, and Jeb Stuart — all exhibited far more overt religious faith than their counterparts. Lee was an Episcopalian; Jackson was a Presbyterian. By contrast, Northern generals like Grant, Sherman, and Philip Sheridan were far more restrained in their religious expression.

Gallagher particularly emphasizes that this difference was reflected not only in personal temperament but also clearly in their official documents. The formal battle reports and correspondence of Southern generals were filled with religious references and allusions at a density far exceeding those found in Grant's or Sherman's papers.

This contrast has deep sociocultural roots. The Southern planter elite was heavily influenced by "cavalier culture," viewing Christian faith as an important marker of gentlemanly identity and moral authority. Southern society was more homogeneous and conservative than the North, with religion playing a central role in maintaining the social hierarchy. Stonewall Jackson's piety was nearly legendary — he strictly observed the Sabbath, prayed at length before battle, and attributed every victory to God. This public devotion also served a political function: it signaled to soldiers and civilians that the Southern cause had divine approval, thereby inspiring spiritual strength under conditions of material scarcity.

This contrast provokes deep reflection: why were the generals of the losing side (the Confederacy ultimately lost) more fervently invoking faith? Perhaps precisely because the South was at a disadvantage in material strength, it needed religious discourse all the more to rally willpower and endow the struggle with sacredness. Religion here served as both spiritual consolation and a strategic narrative resource.

The Double-Edged Nature of Faith: Lessons for Religious Conflicts Today

Gallagher's analysis reveals the complex role of religion in historical conflicts. It could provide soldiers with the courage to face death while also being used to rationalize the most brutal violence; it could comfort the defeated while simultaneously being claimed as moral high ground by both warring parties.

It is worth adding that Abraham Lincoln himself reflected deeply on the paradox of "both sides claiming God is on their side." In his Second Inaugural Address of 1865, Lincoln spoke what are perhaps the most theologically profound words in American political history: "Both read the same Bible and pray to the same God, and each invokes His aid against the other… The Almighty has His own purposes." Lincoln refused to simply claim God for his own side, instead proposing a more humble theological stance — perhaps the war was God's judgment on all of America (not just one side), a punishment for the shared sin of slavery. This theological perspective that transcends the binary opposition of friend and foe remains to this day one of the most profound reflections on the relationship between religion and politics.

This chapter of religious history from the American Civil War reminds us: when a belief system is sufficiently universal and sufficiently flexible, it can simultaneously become a weapon for opposing sides. Understanding this carries profound implications for how we examine conflicts waged in the name of religion, both throughout history and today.

Key Takeaways