Famously opaque on the subject of religion, Lincoln’s personal faith was something even his closest friends said they couldn’t figure out. Though he became more interested in religious questions toward the end of his life, “Honest Abe” never directly identified himself as a Christian—even after he realized it could hurt him politically.
“He once spoke of how not having any kind of noticeable religious profile had levied what he called a tax on his popularity with the voters,” says Allen Guelzo, a professor of Civil War-era studies at Gettysburg College and author of Abraham Lincoln: Redeemer President. “It was something that he was aware of, something he tried to cope with, and yet he wouldn’t go the distance of trying to pretend that he was something that he wasn’t.”
Lincoln’s religious views shifted throughout his life, as most people’s do. He grew up in a Baptist household but was never baptized as a child or an adult, and in his early 20s he was outspoken about his religious skepticism.
“He would actually be aggressive on the subject of unbelief,” Guelzo says. “More than one observer who knew him from those days said that Lincoln could shock people.” For example, he might say the Bible was just an ordinary book, or that Jesus Christ was an illegitimate child. “By the time he moves into his late 20s and early 30s, he has started to temper that because he realizes that doesn’t get him very far politically.”
During his failed campaign to be a Whig nominee for the U.S. House of Representatives in 1843, Lincoln observed that his absence of religious affiliation hurt him. “It was everywhere contended that no Christian ought to go for me, because I belonged to no church,” he wrote. Three years later, after he secured the Whig nomination for the House, he faced more accusations about his faith from his opponent, a revivalist preacher named Peter Cartwright. By then Lincoln had learned not to flout his skepticism, and knew he needed to address his critics.
“That I am not a member of any Christian Church, is true,” he responded in a handbill; “but I have never denied the truth of the Scriptures; and I have never spoken with intentional disrespect of religion in general, or of any denomination of Christians in particular.”
Still, Lincoln didn’t actually say whether he believed in the Christian faith. Instead, “he vigorously denies accusations that were not actually leveled at him,” Guelzo says. “He just deflects.”
Lincoln won that election and continued to be tight-lipped about his personal faith into his 50s. Yet a series of traumatic events—the death of his son Edward Baker in 1850, the outbreak of the Civil War in 1861 and the death of his son William Wallace in 1862—pushed him into a period of religious reflection, in which he thought seriously about what a hypothetical God might want for the U.S. and the institution of slavery.
“In the present civil war it is quite possible that God's purpose is something different from the purpose of either party,” Lincoln wrote in his personal papers in September 1862. “[God] could have either saved or destroyed the Union without a human contest. Yet the contest began. And, having begun He could give the final victory to either side any day. Yet the contest proceeds.”