Tim Keller, pastor of the PCA Church of the Redeemer in New York City, is a fine apologist in the C. S. Lewis tradition. His The Reason for God is very good "mere Christianity" for sophisticated critics.
When I read Christian apologetics, I often find the author can give a solid account of how a Christian should relate to God and other individuals.
As a Christian sociologist, though, I am also looking to see what insight the author can give about how Christians should make and inhabit social structures. In other words, I want more than Christian morality -- I want an account of Christian social ethics.
Ethics is the real weakness of the evangelical side of the church. It is great on "changed lives," but throws up its hands at the architecture of "changed institutions."
In the individualistic traditions of Protestantism -- Baptists and all of their cousins -- this focus only on individuals is built into their DNA.
For the Catholic branch, and the magisterial Reformation strands, of Christianity, though, this neglect is a real weakness. And of the all the magisterial Reformation families -- Reformed, Lutheran, and Anglican -- the Reformed have the most to offer to Protestant social ethics.
Which is why it is disappointing to see so learned and thoughtful a Presbyterian thinker as Tim Keller whiff on Christian ethics. He says at the end of the book that Jesus will come back to redeem the whole world.
But what Christians are meant to do with our social structures in the meantime is left hanging.