I am not a biblical scholar, but I do read the bible often, specifically the New Testament. When I come to the passage below, I'm constantly stumped in how to take it.
"Slaves, obey your earthly masters in everything; and do it, not only when their eye is on you and to win their favor, but with sincerity of heart and reverence for the Lord."
Some translations have "Slaves" as "Servants", which could be an important difference as I am a servant to my job and not a slave, so as a servant I should obey not for purpose of pleasing my boss, but because it is pleasing to the Lord. Taking this translation though, I can't grapple with God telling his people that he loves so much that they should be good slaves. This passage does not say it is okay to own slaves, just how to behave as a slave. I have several ideas on how to take this passage.
If I look at slavery during that time, it is certainly different than slavery as it existed in the U.S. By in large, you were either free or a slave. I don't think they had "employees" as they exist today. This would give more credibility to the "servant" translation. As a servant, you should serve your master on earth as you would your Master in heaven.
I also had the thought that those in power quite often feared slave revolts. They thought that is what Christ came to do. Perhaps Paul inserted this text to put down those fears amongst those in power so that they would be free to carry out the movement. This would then say that we would have to take this text as an aside from God's heart, which I don't think is true. To handle this theory, you must also understand that many of the slaves also thought that Christ would lead a slave revolt. Christ did free them from their slavery to sin, which is eternal freedom as we see in Colossians 3:24.
"since you know that you will receive an inheritance from the Lord as a reward. It is the Lord Christ you are serving."
Another idea, which I think has some merit, is that you should make the most of whatever situation you are in, because regardless of the circumstance, your purpose is to please God and do his work so that you can be a reflection of God's love to those around you, which could include a brutal master. However, this still doesn't answer God's view on slavery.
To get my answer, I had to look back into the old testament and story of Moses. I realized that God hates slavery. When his chosen people were enslaved by the Egyptians, it saddened him. He sent Moses to free his people. In no other time aside from creation and Christ, can I think tat God showed his power to so many in so short a time. Quite often, we rely on faith, but before Pharoh, God demonstrated his power and presense on earth. He went so far as to kill the first born of those that did not carry the blood of the lamb. God freed the slaves. Through the belief in Christs work on the cross, we can all be God's chosen people. Therefore, God would not choose slavery.