Does the Bible condone slavery? That depends on what you mean by "condone". Like death, divorce, and polygamy, slavery is available in God's Law as a last-ditch tool for addressing some tough problems.

Slavery also makes a useful analogy when teaching about relationships and debt. See Paul's letters, for example. This doesn't mean that slavery is noble or desirable or that God necessarily wants anyone to be enslaved. Allowed doesn't mean encouraged.