The problem with the "spirituality" of the church

"Presbyterian churches in the South strongly opposed any interference in the institution of slavery. They developed the idea of the ‘spirituality of the church’ in which the church’s role was not to speak to political issues but only to evangelize, catechize, and build up the church. 

"This was, of course, an intensified form of the more Lutheran version of the two-kingdoms doctrine, but certainly a departure from the way the Reformed churches of Scotland and the Netherlands had related to society. Nevertheless, this emphasis led many doctrinalist churches in the South to shed the older Reformed culturalist impulse....

"Marsden notes many ironies about the Reformed ‘culturalist’ impulse. While the Old School in the South ostensibly held to an apolitical stance- ‘the spirituality of the church’--in reality it became a strong defender of the Southern way of life.13 In other words, to say (in a ‘Two-Kingdom’ way) ‘I’m against social reform, I just want to preach the gospel’ is to be de facto supportive of the cultural status quo, and therefore to be a cultural conservative. “Spirituality of the Church” proponents like Thornwell and Dabney ended up as de facto supporters of slavery, and so they were culturally engaged after all."

-- Tim Keller, "What's So Great About the PCA," June, 2010