Post-Modernism and the Emerging Church

This is a video with R.C. Sproul, Al Mohler, and Ravi Zacharias discussing post-modernism, modernism, liberalism, and the emergent church. The question is asked, Is there any real difference among the four? I'll reserve my comments for later, but the comment about Mohler being the pre-eminent scholar of postmoderism and the emerging church is unfortunate.