Quoting Brian Gerrish, Eric Parker helpfully explains why Martin Luther said what he did about “reason”:
Because reason belongs to the natural sphere, Luther will not allow that it is competent to judge in matters of faith; and yet, because faith comes through the hearing and understanding of the Word, Luther found himself bound to concede that reason – man’s rationality in the broadest sense – was, when regenerate, faith’s indispensable tool (Grace and Reason, 25-27).
