Slavery has been going on for a long while, probably it is always there. Each person uses a slave to do what he doesn't want to do. Most people use a slave to do the dirty work.

It was different now after Jesus had died in the New Testament bringing the kingdom of God back to those who had believed. Free men and slaves they can be set free, not from slavery but doing things differently. Instead of being slaves to Satan doing evil things, we had to be slaves for God instead, doing righteous deeds.

God had created man to be special like himself. He wanted man to be free from slavery and serve him, not to serve the devil.