On a couple points...

Generally, I have found from careful study of the original languages and meanings that the so called "contradictions" in the Bible are in the minds of the uneducated reader only. Also the idea that Christ/God etc are real yet the Bible is inaccurate is to accept the notion that an all powerful God who can create the world is somehow unable to preserve the integrity of his only Book or truly inspire and direct it's authors. This isnt even logical.

As for slavery...it is true that Columbus, a devout Catholic, introduced slavery to this hemisphere with the blessing of the church which regard heathen as heritics deserving of death anyway. It is also true that southern protestants were steeped in the tradition/greed of slavery. In truth our whole country has suffered because of it and it continues to effect us to this day....which stands to reason...."...visiting the iniquity of the fathers upon the children unto the third and fourth generation..."...the effects of sins are passed down.