1Co 1 Corinthians, chapter First Epistle to the Corinthians, chapter 7
In general, each person should remain in the status that he had before he became a believer.
1 Corinthians 7:17-24
If one of you was a slave when you (sg) became a Christian [RHQ], do not be concerned about it. However, if you get an opportunity to be free, do what you need to do to become free.