In Part 1, I unpacked how slavery in the Old and New Testaments were treated. I argued there exists no Biblical foundation for what we call New World Slavery (NWS), a horrible evil that was sadly at times justified by Christians. Here in Part 2, I will briefly go through the opposition of the church to slavery throughout history and conclude that only Christianity was capable of ending NWS.
Slavery and the Historic Church
Slavery declined in the Greco-Roman world with the decline of the Roman empire itself and the rise of the feudal system, which was much different from slavery (serfs had rights, could own property, and were not sold). Additionally, with the influence of the state over the church in Europe from the 4th Century through the rise of NWS in the 16th Century, most Europeans were at least nominally Christian and forbidden from enslaving other Christians. Slavery still existed, though, as seen by those in the church feeling the need to either address it positively or negatively. There were Popes who endorsed slavery to some extent, such as Pope Gregory I (590 – 604) and Pope Gregory XI (1370 – 1378), while others in the church just remained indifferent or saw no conflict with Christianity and slavery. But, as the church became aware of race-based slavery initiated by kidnapping, it was immediately condemned at the highest levels as discussed below.
In the second century, the early Christian apologist Justin Martyr argued against the buying and selling of children in the Roman empire for prostitution. St. Augustine of Hippo (354 – 430), one of the most influential theologians, never argued for the end of slavery in the Roman empire but neither did he offer an endorsement of it. His thoughts on the issue were certainly complex. He assessed slavery as a result of original sin, and slaves were such either because of their sinful nature or because of the sin of others; he did not agree that slavery was natural to man. St. Augustine’s views introduced a moral concern regarding slavery which continued and laid a foundation against secular philosophies that slaves were naturally inferior.
Into the Middle Ages, Saint Bathilde (wife of King Colvis III) started a campaign to both end slave trading and free slaves and Saint Anskar championed the ending of the Viking slave trade in 851 A.D. Both kings and bishops forbid the enslavement of other Christians into the 11th Century (including William the Conqueror, Saint Wulfstan, and Saint Anselm).
As the Age of Discovery drove Europeans west, Eugene IV (Bishop of Rome, 1431 – 1447) issued a bull, Sicut Dudum, which condemned the enslavement of the native inhabitants of the Canary Islands. In 1537, Pope Paul III began a series of writings, including a bull, Sublimis Deus, intended for all Christians, issued penalties for those who did engage in slave trading, and noted the Indians of the New World were human beings. Upon learning of NWS, Paul III noted this slavery was “unheard of until now” and that there was no moral justification for such slavery. Tradition then builds late in the 16th Century and onward, as other Popes would quote Paul III’s teachings on slavery. In 1686 the Congregation of the Holy Office, through a series of questions and answers, openly condemned the kidnapping and enslavement of the people of Africa. Condemnations from Popes continued in 1741, 1815 and 1839, well into the height of the New World slave trade.
An Apologetic Response through Abolition
Understanding the influences of the abolition movement provides an apologetic response to those who charge Christianity was responsible for NWS. The rise of NWS coincides with the Age of Reason, and I would argue that is not a coincidence. The Age of Reason signified a return to much of Greco-Roman thinking in which philosophers such as Aristotle and Plato were proponents of slavery. The intellects of the Age of Reason, led by men such as Thomas Jefferson, John Locke, and David Hume, provided no objection to NWS with their philosophies. Their influence grew as the Roman Catholic churches weakened, especially in the New World, which explains why the Pope’s consistent condemnations against slavery went unheeded.
But just over a century earlier, the Reformation had begun. By the time NWS had increased, the foundation for abolition was already built within emerging Evangelical Christianity. Among other issues, a return to the Bible as the sole authority of the faith along with the pursuit of a more genuine Christianity defined the Evangelicals. It was from changed hearts and more of the Bible, not less, that the fight for freedom arose; not from a Pope, or a single church or denomination, but from the body of Christ standing on Scripture understanding it was a sin to hold and trade other humans as property.
The Quakers in America were the first in turning abolition into a movement as opposed to just individual voices.  A significant development was the publication of anti-slavery tracts highlighting such verses as Matthew 25:40 (English Standard Versions) which Jesus said “…Truly, I say to you, as you did it to one of the least of these my brothers, you did it to me.” They were also the first to forbid the owning and trading of slaves within their communities. Eventually, more denominations came on board with the abolition movement, such as Methodist, Presbyterians, and Congregationalist, leading to the formations in 1833of the American Anti-Slavery Society. By 1838 there were over 1000 chapters and of the traveling representatives, over half were ordained ministers, and three-quarters of the local members were clergy.
It would be the abolitionist in England who would see victory first. Anti-slavery societies of Evangelical Christians formed similarly to the movement in North America. The founding father of the Methodist Church, John Wesley, published his Thoughts Upon Slavery in 1774 which brought the growing number of Methodist onboard against Slavery. John Newton, who once captained a slave ship, and upon his conversion to Christianity penned “Amazing Grace,” was also influential. And then, of course, William Wilberforce, who tirelessly fought for abolition within the British Parliament. His speeches centered on the slaves as “children of God and thus worthy of the birthright of freedom.” Summarizing the movement, Stark states that abolitionist “spoke almost exclusively in the language of Christian faith.”, while the pro-slavery clergy was “overwhelmingly secular” in their defense of slavery often invoking concepts of liberty and states’ rights as opposed to any religious language.
One of the most striking examples of the importance of Christianity to the Abolition movement was the adoption of Christianity within the slave population in North America. Vincent Carol and David Shiflett argue “…Christianity’s importance to abolitionists may have been equaled only by its importance to slaves themselves, who were sustained by its message of hope and its assurance of a liberty that transcended their current bondage.” How could Christianity, on the one hand, justify slavery while on the other be the hope of its victims? I would argue it couldn’t; the fact abolition prevailed led by Evangelicals while Christianity arose from the slave population demonstrates the correct Christian view against slavery.
There were those in the church who, at times, were proponents of slavery. But their endorsement does not overrule what the Bible itself endorses; particular descriptions of slavery do not equal a prescription of oppressive slavery. Those who refuse to explore Christianity because of their moral objections to slavery are denying to explore the only worldview that contains both their moral opposition as well as the grounding to fight slavery. An examination of church history and the abolition movement reveals an undercurrent of anti-slavery language and ethics firmly rooted in God’s consistent Word. Christianity, and more specifically Reformed Christianity, was the greatest force against NWS. It not only commanded its followers to fight for the oppressed, but it also provided the only worldview that could objectively argue all men have intrinsic value, making slavery an unjustifiable evil.
Resources and further reading:
 Rodney Stark, For the Glory of God (Princeton, NJ: Princeton University Press, 2003, 299-300.
 Vincent Carroll and David Shiflett, Christianity on Trial: Arguments Against Anti-Religious Bigotry (New York, NY: Encounter Books, 2002), 29.
 Ibid., 26.
 Peter Garney, Ideas of Slavery from Aristotle to Augustine (New York, NY: Cambridge University Press, 1996), 218.
 Stark, For the Glory of God, 329.
 Joel S. Panzer, The Popes and Slavery (Staten Island, NY: Alba House, 1996), 7.
 Ibid., 16-17.
 Ibid., 20-22.
 Ibid., 37.
 Carroll and Shiflett, Christianity on Trial, 29.
 Bruce L. Shelly, Church History in Plain Language, 4th ed. (Nashville, TN: Thomas Nelson, 2013), 325.
 Carroll and Shiflett, Christianity on Trial, 31.
 Stark, For the Glory of God, 330.
 Mark A. Noll, Turning Points: Decisive Moments in the History of Christianity, 3rd ed. (Grand Rapids, MI: Baker Publishing, 2012), 230.
 Stark, Glory of God, 340
 Ibid., 341.
 Carroll and Shiflett, Christianity on Trial, 41.
 Ibid., 37.
 Stark, Glory of God, 344.
 Carroll and Shiflett, Christianity on Trial, 47.