The following is excerpted from the so-far fantastic The Southern Tradition, by Eugene Genovese. It was published in 1994, and the lectures it is based on given earlier.
Still, whatever may go on in New York and the Bay Area, in Dixie and across much of the American heartland a lot of folks, black and white, still attend churches that preach the old-fashioned notion that religious beliefs should have something to do with morals and therefore with politics. Yet, contrary to Yankee propaganda, southerners have always been more tolerant of religious differences than northerners. The slave states sent the first two Jews to the United States Senate and would have provided the first Jew to sit on the United States Supreme Court if Judah Benjamin had accepted the proffered nomination. Jews and Catholics, as they freely acknowledged, found a much warmer reception among the slaveholders of the South than among the propertied classes of the North.
There nonetheless remains a fundamental difference between northern and southern versions of religious tolerance. In the North people are wont to say, "You worship God in your way, and we'll worship Him in ours." This delightful formulation says, in effect, that since religion is of little consequence anyway, why argue? In contrast, the southern version, well expressed in an old joke, says: "You worship God in your way, and we'll worship Him in His." From the early days of the Republic, when the Baptists led the fight for religious freedom and the separation of church and state, white southerners have done rather well in living together with mutual respect and tolerance for each other's religious views. Always reminding themselves of human frailty, they are perfectly tolerant of some damned fool's right to choose eternal damnation. But they are not about to pretend that they regard another's religion as intrinsically equal to their own.
The churches of the Old South held the line for Christian orthodoxy during many decades of backsliding by their northern counterparts. Unitarianism reigned at Harvard and among the Boston elite. More tellingly, almost everywhere in the North the mainstream churches were steadily abandoning the doctrines of original sin and human depravity for a rosier and more progressive view of God and human nature. After the War for Southern Independence they completed the process, and today we have purportedly mainstream churches that are still reeling under the theological sea change initiated by Friedrich Schleiermacher and fortified by Adolf von Harnack's assault on church dogmatics. We have, that is, churches that tolerate, when they do not encourage, the heresies of Arianism and Socinianism and happily treat other doctrines long thought essential to Christianity as so many metaphors, not to say embarrassments. It is now possible to join some professedly Christian churches without accepting Christ as your savior or even believing in God.