Slavery was common in the ancient world. Sometimes, it was the only option for people who were very poor. Many slaves believed the gods had abandoned them. Because the Lord cares for those in this difficult situation, his followers must also care.
In time, the message that Jesus Christ died for all people everywhere changed how believers viewed slavery. If Christ died for everyone, then all people have equal value before God.
This truth made slavery impossible to defend in the long term (Galatians 3:28).