There's an exceptional book on this called "The Civil War as a Theological Crisis" by Mark Noll. In it, he details how there was another battle that raged before, during, and after the Civil War that was purely theological. I'm on mobile so I won't write a novel here but, essentially, you had religious people on all sides of the issue. Yes, you had the Christians in the South (mostly) arguing for slavery by saying that the Bible does not expressly prohibit slavery and, in fact, encourages it at certain points. Even in the New Testament, the Bible simply treats slavery as a natural condition rather than being a point of contention. The Northern Christians, then, would argue the high view: that the spirit of the Bible is to "do unto others as you would have them do unto you" and that to enslave is not what you would want done to you. The South then went with the whole "yes we would, because we were able to bring the light of God to the slaves through slavery thus saving their souls." Of course, Christians in the North thought that was silly but the argument was there nonetheless.

Then you had arguments concerning providence. "God will make the right ones victorious." That turned out to be a big whoopdidoo because after the South lost, they went with the "God works in mysterious ways" argument.

In short, there were Christians, even conservative Christians on either side arguing different views on slavery. This is another one of those instances wherein we see that humans are diverse critters and Christians aren't exempt from that. As such, different Christians had different opinions concerning slavery throughout the country.

Anyway, again, sorry for the short answer but definitely check out that book. It's a fun read.

Edited for grammar, darn phone.

Every state had a large Christian majority, so it would be inaccurate to assign Christianity more to the Southern states than the Northern in the antebellum period. I also wouldn't expect all Christians throughout history to have the same idea of what is "Christ-like." To use another example, while it is difficult to imagine Jesus of Nazareth dropping bombs on a city, most Christian sects accept that violence under some circumstances can be justified, deriving originally from the Just War doctrines of Augustine and Aquinas.

There were both religious and non-religious arguments for slavery and abolition. One major Christian sect, the Quakers (or Society of Friends) were prominent in abolition movements in the United States and Britain. They were moved by their faith and abolitionist convictions to organize both for an end to slavery ultimately and for the Underground Railroad in the meantime. The Quakers were no less Christian than the Southern Baptists, and Christianity can no more or less be ascribed to abolition as to slavery.

Brycchan Carey has written extensively on the role of Quakers in the abolitionist movement. Check out Quakers and Abolition out of University of Illinois Press and From Peace to Freedom: Quaker Rhetoric and the Birth of American Antislavery, 1658-1761 out of Yale University Press.

As for the part of your question that refers to conservative feelings, I'd say that what it means to be conservative changes by time and place. "Conservative" (like "liberal" or "progressive" or "radical" or "reactionary") is a relative term. It does not contain an innate ideology like monarchism, capitalism, communism, or anarchism, to name a few movements defined by specific beliefs. To be "conservative" is, fairly self-explanatory, to advocate for the conservation of a real or perceived traditional social order in any given society. A conservative in 1789 France would most likely be a monarchist, while a conservative in 1978 America would almost certainly be a (small-R) republican. Similarly, if the present and accepted social order includes slavery, one defined by their desire to preserve the current or traditional social order would likely support keeping that institution largely unchanged.

If you're trying to wrap your head around how people dealt with their attitudes towards slaves socially, I would suggest Orlando Patterson's Slavery and Social Death: A Comparative Study which doesn't speak to just American Slavery but slavery as a broader institution. In many ways, arguments centered around economics or other "practical" concerns because the slaves were simply not considered full human beings in a social sense.