My colleague shared a quote with me recently that is blog-post worthy. It encapsulates the liberal/progressive approach to public theology, which takes a common Christian scholarly sentiment that “all truth is God’s truth,” and runs that all the way down to mean that, “yes, seriously, all truth is God’s truth, and that conviction must shape the way we actually seek and determine what is true.”
For Schleiermacher, the only possible Christian theology was a ‘public’ theology, one whose warrants could be made clear and whose statements would be intelligible outside the bounds of the believing community. Those statements must also not be in conflict with other, nontheological claims to truth.
from Claude Welch’s Protestant Thought in the Nineteenth Century, Vol. 1, p. 62.