How can we hold the bible up as a moral compass when it so explicitly endorses and codifies the rules for SLAVERY? [Spirituality & Religion]

[youtube=https://www.youtube.com/watch?v=TDL0FttPX-4?t=293]

I think i got this link right. If not, the discussions really starts around 4:50.

I wonder how familiar the average christian is with this subject.