Both read the same Bible and pray to the same God, and each invokes His aid against the other. It may seem strange that any men should dare to ask a just God’s assistance in wringing their bread from the sweat of other men’s faces, but let us judge not, that we be not judged. The prayers of both could not be answered. That of neither has been answered fully. The Almighty has His own purposes. “Woe unto the world because of offenses; for it must needs be that offenses come, but woe to that man by whom the offense cometh.” If we shall suppose that American slavery is one of those offenses which, in the providence of God, must needs come, but which, having continued through His appointed time, He now wills to remove, and that He gives to both North and South this terrible war as the woe due to those by whom the offense came, shall we discern therein any departure from those divine attributes which the believers in a living God always ascribe to Him? Fondly do we hope, fervently do we pray, that this mighty scourge of war may speedily pass away. Yet, if God wills that it continue until all the wealth piled by the bondsman’s two hundred and fifty years of unrequited toil shall be sunk, and until every drop of blood drawn with the lash shall be paid by another drawn with the sword, as was said three thousand years ago, so still it must be said “the judgments of the Lord are true and righteous altogether.”
Abraham Lincoln, Second Inaugural
A look at religion in the Civil War from the internet series the Civil War in Four Minutes. Most people on both sides, as Lincoln noted in his Second Inaugural, assumed God was on their side. Some viewed their causes as crusades. Typical of those who embraced that interpretation is a Union officer who upbraided a chaplain who had given a stern sermon to the men of his regiment on the pains of Hell, and informed him that every one of his boys who fell in this great fight for human liberty was going straight to Heaven and he would allow no other doctrine to be preached while he was in command of the regiment.
Perhaps the most insightful view was that embraced by Abraham Lincoln, Robert E. Lee and others who saw the War as the punishment for national sins. Rather than a crusade, the War was a chastisement that God was using for His purposes. I think there is much wisdom in this view. God often brings good out of human weakness, folly and even sin, and out of the Civil War, with all of its ghastly loss of life, came freedom for the slaves and a united nation.
As was usual, Robert E. Lee pointed the way forward. With his strong faith in God he accepted the end of slavery, which he claimed to rejoice in, and the preservation of the Union. When a woman wrote him a letter filled with her hatred of Yankees, Lee wrote back to her:
Madam, don’t bring up your sons to detest the United States Government. Recollect that we form one country now. Abandon all these local animosities, and make your sons Americans.
John Esten Cooke recalled this incident with Lee after the War:
“One day last autumn the writer saw General Lee standing at his gate, talking pleasantly to an humbly-clad man, who seemed very much pleased at the cordial courtesy of the great chieftain, and turned off, evidently delighted, as we came up. After exchanging salutations, the general said, pointing to the retreating form, ‘That is one of our old soldiers, who is in necessitous circumstances.’ I took it for granted that it was some veteran Confederate, when the noble-hearted chieftain quietly added, ‘He fought on the other side, but we must not think of that.’ I afterward ascertained–not from General Lee, for he never alluded to his charities–that he had not only spoken kindly to this ‘old soldier’ who had ‘fought on the other side,’ but had sent him on his way rejoicing in a liberal contribution to his necessities.”