Slavery in Rome in the time that Paul writes his letter to the Ephesians was a given- and something that everyone understood and even some within the church had first hand experience. Paul gives instructions to slaves and masters on how they should relate to one another. We may not be slaves or slave owners, but we do have relationships at work where we are under the authority or in positions of authority over other people. Work relationships can difficult, but work can also be a mission field ripe with the opportunity to take ground for the Kingdom of God.
