Why is slavery permitted in the bible?

I can't see that slavery is encouraged by the bible but as someone already said it was a vital part in the community at that time. It says though in the new testament that a slave should keep being slave even if he/she was saved. In the letter of Philemon we can see how the author ask for freedom for a slave. I think the whole bible is a freedom message to people that are slaves, because it says that there are something more to come except for what we already can see.

the bible was written in a time where slavery was a vital part of the economy. the people back then had different morals than we do now, so what they write, and the bible is one of the texts they wrote, reflects their moral beliefs.