Ephesians 6:5-9 Paul's Instruction To Slaves and Masters

Our text this morning is Ephesians 6:5-9,

Bondservants, obey your earthly masters with fear and trembling, with a sincere heart, as you would Christ, not by the way of eye-service, as people-pleasers, but as bondservants of Christ, doing the will of God from the heart, rendering service with a good will as to the Lord and not to man, knowing that whatever good anyone does, this he will receive back from the Lord, whether he is a bondservant or is free. Masters, do the same to them, and stop your threatening, knowing that he who is both their Master and yours is in heaven, and that there is no partiality with him.

I have often tried to imagine Paul as he would stand before a congregation that was full of slaves and masters and speak on this issue. I would imagine that it took a lot of courage for Paul to stand up before these Christian congregations and say,