Given the widespread consensus in contemporary thought that slavery is wrong, why does the Bible seem strangely ambivalent concerning this institutional horror? In fact, one looks in vain in either the Old or New Testaments for an overt call for the abolition of slavery. Neither does the Bible prophetically thunder against its evils as an institution. In fact, as shocking as this sounds, slavery was widespread and generally accepted by almost everyone in ancient times as a basic and accepted aspect of society.
Having said that, however, the Bible does address the subject of slavery in certain ways that bear highlighting. First, compared to the practices and laws of other nations of that time and place, the Old Testament “softens” a lot of the stipulations surrounding its practice. Masters were not to be harsh toward slaves, provisions were made for their well-being (e.g., Deuteronomy 15-13-14), and they were offered freedom after only seven years of service. Exodus 21 gives examples of the appropriate ways in which the Israelites were to treat slaves.
Part of the reason for this “softening” of slavery was because the Israelites themselves had been slaves in Egypt. This harsh bondage was something for which the Egyptians were punished very harshly by God. Thus, the Israelites were to treat their own slaves kindly (e.g., Deuteronomy 24:17-18) and not be guilty of an offense in kind.
Although the Old Testament undercuts the harshness and length of slavery, it was still widespread and accepted in the ancient Near East. This acceptance of slavery as a normal social institution continued up until the time of the Roman Empire in the first century. In fact, by the time of the New Testament, it is estimated that as many as one-third of the Roman empire consisted of slaves!
Still, slavery at that time (as well as in the ancient Near East) was not directly parallel or comparable to slavery in the modern era. First, slavery was not necessarily based on race. It often resulted from foreign conquest or from being unable to pay a debt. Second, being able to move up and out of slavery was both possible and sometimes even common. Third, many “slaves” were actually quite educated and skilled workers, being paid decent wages which were enough for them to buy personal goods and save for the future.
Nevertheless, as a whole, slavery was still a brutal and exploitative institution, and while the Old and New Testaments do not crusade for its abolishment, there is no doubt that the New Testament especially sows the seeds for the condemnation and abolition of slavery after the time of Christ. See, for example, verses like 1 Corinthians 7:21-23, 12:13, Galatians 3:28, Colossians 3:11, and 1 Timothy 1:10. In this regard, the book of Philemon is especially significant. Here Paul tells Philemon to consider his escaped slave, Onesimus, a “beloved brother” and equal in Christ. All these passages and more clearly point toward human equality under the gospel of Christ and away from the degradation and oppression of institutional slavery.
Many feel (and I agree) that in the progress of revelation, this was the moral trajectory God was moving toward with its foundation in the fact that all human beings—male and female—are created in His image (Genesis 1:26-27) and therefore worthy of equal respect and opportunities for flourishing.
Ultimately, the Bible neither overtly condemns nor openly condones slavery. It does, however, strongly mitigate and change the nature of the institution such that its teachings eventually led to an almost universal renunciation and abolition of it in the modern era, something that would have been impossible apart from the biblical view of the equal value and dignity of every human being made in the image of God.