“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.” (Ephesians 6:5–9 ESV).
The situation of Paul’s day was horrific. Slavery teemed throughout the Roman world. Some estimate as much as half the empire was enslaved, a fact which was cause for concern amongst the ruling class. A rebellion was feared. Not only large in number, but slaves were also often highly educated, working as physicians, lawyers, and teachers. But we should not make the mistake of thinking it was not still a brutal institution, for all the education and status in the world could not serve to alleviate the pain of slavery. Slaves were bought and sold. Barbaric treatment of slaves was legal. Many slaves ran away, as even our biblical record attests (Philemon).
By the time Paul wrote his letters, many slaves throughout the empire had heard the gospel of redemption found in Christ Jesus and had converted to Christianity, so Paul found himself addressing a church with many a slave. Here, in Ephesians, he wrote to them, teaching them how to conduct themselves in the fear and trembling, living out their lives as servants of Christ.
Now, the concept of slavery ought to be abhorrent to every Christian in every historical period, but it is especially repugnant in a western culture familiar with American (and British) forms of slavery. That version of the abomination was based on race, trading life for money, skin for produce. With that blot on our minds, we might ask, why did Paul not condemn slavery?
Some have noted pragmatic and circumstantial reasons. Pragmatic, because Christianity was a small movement at the point Paul wrote Ephesians, ill-prepared to dismantle an entire societal structure. These Christians would not have thought of themselves qualified to break up the institution of slavery, replacing it with gospel love. Circumstantial, in that some have found evidence that slavery was slowing by the time Paul wrote, with some Romans granting freedom to their slaves. Such a large population of slaves had, apparently, required the ruling class to soften conditions lest a dreaded slave rebellion break out.
However, there seem to be gospel reasons as well. The plan of God did not seem to be the immediate, violent upheaval of the system, but a systematic medication of the minds that had previously adopted slavery. The gospel could do this slow, methodical work. As the gospel message spread, so did the concept that all of humanity is created equal in the sight of God. Aristotle had said, “The slave is a tool with a soul." But the Christian came along, more enlightened than Aristotle, and said, “The slave is a human with a soul, equal to me in the sight of God.” As this perspective spread, so did the death of the Roman form of slavery.
There is a hint about this in Paul's writing here in Ephesians. In this section, he addressed husbands, fathers, and masters, along with wives, children, and slaves. He grouped his teachings to each of them together. When addressing marriage, he quoted from the Old Testament. When addressing families, he quoted from the Old Testament. When addressing the slave-master dynamic, no such Old Testament quote is found. The suggestion is subtle but real. He knew marriage and family biblical institutions, divine creations. But he saw slavery as wholly manmade and in need of inevitable death and demise. As the gospel helped people see value in other human beings, thus creating an abhorrence of slavery, Paul seemed to have envisioned a slow death to this disgusting creation of sinful humanity.
The gospel always does this work. It always elevates the way we see other human beings. Many modern societies have benefited from this gospel work, understanding, now, that women, children, and the working class share equality in God's sight with men, fathers, and the upper class. Much work is left, however, for sins like racism, abortion, pornography, and abuse all say, “I am more important than you.” Remember, sin causes humanity to objectify and devalue life, but the gospel causes humanity to value all life.