“ For all slaveholders with whom I have ever met, religious slaveholders are the worst. I have found them, almost invariably, the vilest, meanest and basest of their class. Exceptions there may be, but this is true of religious slaveholders, as a class. ”
 Frederick Douglass, My Bondage and My Freedom (1855). copy citation

add

“I assert most unhesitatingly, that the religion of the south—as I have observed it and proved it—is a mere covering for the most horrid crimes; the justifier of the most appalling barbarity; a sanctifier of the most hateful frauds; and a secure shelter, under which the darkest, foulest, grossest, and most infernal abominations fester and flourish. Were I again to be reduced to the condition of a slave, next to that calamity, I should regard the fact of being the slave of a religious slaveholder, the greatest that could befall me. For all slaveholders with whom I have ever met, religious slaveholders are the worst. I have found them, almost invariably, the vilest, meanest and basest of their class. Exceptions there may be, but this is true of religious slaveholders, as a class. It is not for me to explain the fact. Others may do that; I simply state it as a fact, and leave the theological, and psychological inquiry, which it raises, to be decided by others more competent than myself.” source