That's pretty disheartening to see. I believe an important concept for all Christians to recognize is the idea of Present Truth. Biblically, the views expressed in scripture are relative to the times they were written in, I.E., slavery was a common practice in much of scripture, therefore the writers in scripture did not think much of it.
In the same way, as a culture and as a world (for the most part) the "modern" world recognizes that the concept of owning another human being is unethical and inhumane. Present Truth would encourage us to embrace that enlightenment, rather than use examples from a book written during a completely different time and culture(s) to justify.
Regardless of whether or not there is a commandment which says "thou shalt not have a slave," slavery has been shown to be wrong as enlightenment increases. Anything less would be blindly following scripture, having no concept of the ethical and moral responsibilities we are also called to, and in reality, mean much more in this life than the "do's" and "don'ts."
Regards yall!
- Raph