...while it's true, shamefully true, that American Christians in the South defended chattel slavery, we need to put this sad fact in context. By the nineteenth century, slavery had existed for a long time, and it was usually not an ethnic or racial thing. Africans had more slaves of their own than were sent to the New World. Muslim slaving trading began centuries before Europeans discovered the New World and it continued longer, being legally abolished in Saudi Arabia in 1962.
Of course, this doesn't mean Christians have no complicity in evils of slavery, but we should remember that slavery was eradicated chiefly due to Christians and Christian nations. The overthrow of slavery [after near universal slavery for almost of all recorded human history] came about from two main factors: the rise of nation states [so it became too dangerous to go raid other peoples] and Christian opposition to its practice.
For all its grave faults, European imperialism is largely responsible for ending slavery. Starting in the nineteenth century, the British stamped out slavery in their Empire, which at that time covered a fourth of the world. They destroyed slave trading ships, made slavery illegal, and blockaded islands and coasts until slavery was shut down. Thomas Sowell, the African-American economists writes, "It would be hard to think of any other crusade pursued so relentlessly for so long by any nation, at such mounting costs, without any economic or tangible benefit to itself." And the crusade was championed by Christians, William Wilberforce chief among them.
Furthermore, it's not was if nineteenth-century Christians were the first ones to object to slavery. Christians didn't begin seeing slavery as being wrong starting in the nineteenth century. As early as the seventh century, Saint Bathilde [wife of King Clovis II] became famous for her campaign to stop slave tranding and free all the slaves in the kingdom. In 851 Saint Anskar began his efforts to halt the Viking slave trade.
In the thirteenth century, Thomas Aquinas argued that slavery was a sin, and a series of popes upheld the position. During the 1430s the Spanish colonized the Canary Islands and began to enslave the native population. Pope Eugene IV issued a bull, giving everyone fifteen days from receipt of his bull, "to restore to their earlier liberty all and each person of either sex who were once residents of said Canary Islands...These people are to be totally and perpetually free and are to be let go without exaction or reception of any money." The bull didn't help much, but that is owing to the weakness of the church's power at the time, not indifference to slavery. Pope Paul III made a similar pronouncement in 1537. Slavery was condemned in papal bulls in 1462, 1537, 1639, 1741, 1815, and 1839. In America, the first abolitionist tract was published in 1700 by Samuel Sewall, a devout Puritan. Meanwhile, Enlightenment bigwigs like Hobbes, Locke, Voltaire, Montesquieu, and Burke all supported slavery. I am not trying to rewrite history here and made the record of the church into one long string of unbroken heroism. But since we get the impression from so many folks, Christians and nonChristians alike, that the church has been an unmitigated disaster on social issues since the beginning of time, we should take the time to get the rest of the story, in context and unsensationalized.
Excerpt from Why We Love The Church by Kevin DeYoung and Ted Kluck