1 Corinthians 7:23
Ye are bought with a price; be not ye the servants of men.
Note 9 at 1Co 7:23: This appears to be contrary to what Paul had just said in 1Co 7:21, but of course, it isn't. Although Paul told slaves to submit here, other instructions to slaves made it clear that they were actually serving Christ, not man (Eph 6:5-7 and Col 3:22-24). When this attitude is adopted, then the bondage is removed from slavery. Christian slaves could not be forced to do what they freely offered to do.
Note 10 at 1Co 7:23: Slavery is not a major issue in the world today as it was in the past. Yet these same principles apply in many areas of our modern-day lives. We could easily substitute the words "employer" and "employee" for "master" and "servant." These truths will work in any relationship where one person is in authority over another.