In the Series Preface to the Brazos Theological Commentary on the Bible, the first volume of which was Jaroslav Pelikan’s volume on Acts, R.R. Reno writes:
“…doctrine is intrinsically fluid on the margins and most powerful as a habit of mind rather than a list of propositions, ….”
I find this a fascinating statement; the second half of the sentence I readily agree with; clearly a set of propositions fails it objective if not internalized. The first half of the sentence is more difficult to accept.
Upon reflection, however, it seems to me that because doctrine is “intrinsically fluid” (the reflections of man upon the absolute truths of God) propositional formulations like creeds and confessions exist to provide boundaries for the “fluid” nature of doctrinal (read “theological”) speculation.
 “Series Preface” by R.R. Reno in.Jaroslav Pelikan, Acts: Brazos Theological Commentary on the Bible (Grand Rapids, MI: Brazos Press, 2005)