How did some slave owners defend their right to own slaves?

some slave owning southerners justified slavery by using the bible, and interpreting scripture or divine right to do so. (blessed are the poor, others said that black and white were created differently by God for their current purposes: master & slave) Some took the 'paternal' view saying that the slaves weren't ready or intelligent enough to survive without the guiding protecting hand of a master. as well as their influence on their slaves in bringing them to Christianity and spiritually rescuing them from dying in hell etc.