Less cost to everyone. Every slave could have been bought out in 1861, and been freed immediately, for less cost than the 4 years of war. Or you could have come up with a 3 year plan, and had a reasonable period of adjustment, without violence.
How a slave buyout would have saved money and pain over the choice to engage in the Civil Warwww.gongol.com
Literally every western nation besides the United States managed to outlaw slavery without bloodshed. Even ignoring the costs of taking 3.8 million men out of the labor force, widespread property destruction, and the lingering hatred that leads people to violently destroy monuments to this very day, it would have been three hundred million dollars less to simply buy and free every slave, rather than fighting a bloody war to do so. So while slavery was certainly wrong, invading a country in order to end it, when there was a peaceful option, was just as wrong, if not worse. If we were honest with ourselves, and didn’t immediately try to defend the Southern perspective, or the Union perspective, I think we’d have a greater appreciation for just how complex and tragic the Civil War was.
As for Christian thought, I’ll refer you to Douglas Wilson (https://dougwils.com/). He addresses the Old Testament vs. New Testament Leviticus stuff in the documentary “Free Speech Apocalypse”, and despite the fact that I think he’s spewing a lot of nonsense a lot of the time, the man is considered, reasoned, and gracious.
As for ISIS and Boko Haram, I would be lying if I said I wouldn’t cheer their long and agonizing deaths, and the destruction or denial of all they deem sacred or holy, but despite my own personal hatred for what these people stand for and what they do, in order not to become them, I have to control my latent angry impulses. I understand that while it might seem like a good idea to invade Nigeria to free the slaves, and to hold Mecca hostage against terrorists (imagine blockading Mecca for one year for every terror attack preventing the Hajj for all of the islamic world) it is not a moral choice unless it is a truly a last resort. The War Between The States was not a last resort.
I will, however, note my own hypocrisy when it comes to my support of the US intervention in WWII, and the terrible, bloody things we did to civilians all throughout that war — but I think I manage to rationalize my cognitive dissonance there by casting Germany and Japan as existential threats to the greater world. Even as I castigate Sherman, I have to reluctantly accept that his “total war” theory has perverse merit.
As a complete aside, one of the ways I imagined we could have won the war in Afghanistan would have been to remove every girl 12 years and younger from their families, and create the first all-woman army in the world. 17 years later, we’d have senior cadre about 29 years old, and a bunch of buck privates ready to do battle with the Taliban. Limiting firearms ownership to women would have eliminated misogyny within a generation. It was a pipe dream, to be sure, but it would have been a wonderful thing to see a bunch of jihadis smushed to bits by chicks with guns.