Slavery was a common practice in the ancient world and not the social issue that it is today. In dealing with the subject of slavery in the bible, first a distinction should be made between slavery and servitude. Slavery is the kidnapping and selling of men and women, such as with the African slave trade. That kind of slavery is explicitly condemned in the bible:
Servants also had to be treated in an ethical manner. A female servant was guaranteed food, clothing, and marriage rights. If her master did not provide these things for her she would be free to go (Exd 21:10-11). If a man beat his servant to death he would be punished for it (Exd 21:20). If a man struck the eye of his servant or knocked out a tooth, the servant was free to leave (Exd 21:26-27). Slaves that ran away from their masters, presumably from mistreatment, could seek asylum in other towns without being punished for it. (Deu 23:15).
It is Christian values that placed value on life and upon individuals. It was ultimately those biblical values that helped put an end to slavery in America and in fact many of the abolitionists were Christians. We often look through the lens of history with 21st century ethics. But the ancient world was very different and much more harsh. They sometimes had to do things in order to survive that we don't.
You shall not steal. (Exd 20:15)
He who kidnaps a man and sells him, or if he is found in his hand, shall surely be put to death. (Exd 21:16)
If a man is found kidnapping any of his brethren of the children of Israel, and mistreats him or sells him, then that kidnapper shall die; and you shall put away the evil from among you. (Deu 24:7)There are many diverse reasons how and why people became slaves, and it wasn't always a cut and dried issue. In the Old Testament slaves were more akin to indentured servants. People would sometimes sell themselves as slaves if they were unable to provide for themselves or couldn't repay their debts (Lev 25:39-40). In some cases servants pledged lifelong servitude to their masters by piercing there ear with an awl. (Exd 21:5-6). In other cases people would become slaves as a punishment, thieves would be sold into slavery if they could not pay for restitution (Exd 22:3). However, being a slave was not always a permanent situation. Servants could buy their freedom and Hebrew servants who were bought were free to go after 7 years, unless they chose to stay as some did (Exd 21:2).
Servants also had to be treated in an ethical manner. A female servant was guaranteed food, clothing, and marriage rights. If her master did not provide these things for her she would be free to go (Exd 21:10-11). If a man beat his servant to death he would be punished for it (Exd 21:20). If a man struck the eye of his servant or knocked out a tooth, the servant was free to leave (Exd 21:26-27). Slaves that ran away from their masters, presumably from mistreatment, could seek asylum in other towns without being punished for it. (Deu 23:15).
It is Christian values that placed value on life and upon individuals. It was ultimately those biblical values that helped put an end to slavery in America and in fact many of the abolitionists were Christians. We often look through the lens of history with 21st century ethics. But the ancient world was very different and much more harsh. They sometimes had to do things in order to survive that we don't.