Prophecy Redefined

Since the Strange Fire conference I am beginning to question the different between big A apostle and little a apostle, along with big P prophecy and little p prophecy: Prophecy Redefined:

"Following Grudem, Piper posits a radical discontinuity between prophecy in the two Testaments, as if Old Testament prophecy is infallible and authoritative, while the New Testament gift of prophecy is not. But that bold conclusion is nothing more than a highly questionable inference. However, if such a radical redefinition of this gift had taken place between the Old Testament and New Testament eras, we would be right to expect explicit statements in Scripture to inform us of this change."