"Slaves, obey your earthly masters with deep respect and fear. Serve them sincerely as you would serve Christ." (Ephesians 6:5 NLT)
"Slaves, submit yourselves to your masters with all respect, not only to those who are good and considerate, but also to those who are harsh." (1 Peter 2:18)
"All who are under the yoke of slavery should consider their masters worthy of full respect, so that God's name and our teaching may not be slandered." (1 Timothy 6:1)
"Students are not greater than their teacher, and slaves are not greater than their master." (Matthew 10:24)
In these verses we see Jesus telling slaves they have to submit to their masters even if the masters are abusive, and that slaves are not equal human beings. He also said to submit even if the slaves fear for their lives.

