Pastor Kevin DeYoung responds to the assertion that Christians can no longer hold to traditional views of homosexuality. The argument usually goes like this: "You Christians are on the wrong side of history with regard to homosexuality. Look at slavery, for instance." DeYoung writes:

While it's true that Christians in the South often defended chattel slavery, this was not the position of the entire American church, and certainly not the universal position of the church throughout history. Unlike slavery, the church has always been convinced (until very recently) that homosexual behavior is sinful. There are no biblical passages that suggest the contrary. There are, however, passages in Scripture that encourage the freeing of slaves (Philem. 15—16) and condemn capturing another human being and selling him into slavery (Ex. 21:16; 1 Tim. 1:8—10).

Furthermore, it's not as if Christians never spoke against the institution until the nineteenth century.

As early as the seventh century, Saith Bathilde (wife of King Clovis III) campaigned to stop slave-trading and free all slaves. In the ninth century Saint Anskar worked to halt the Viking slave trade. In the thirteenth century, Thomas Aquinas argued that slavery was a sin, a position upheld by a series of popes after him. In the fifteenth century, after the Spanish colonized the Canary Islands and began to enslave the native population, Pope Eugene IV gave everyone 15 days "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." 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.

Clearly, the church's opposition to slavery is not a recent phenomenon. We do not find anything like this long track record when it comes to the church supporting homosexual practice.