(W)hat the Reformation began in less than half a century, orthodox Protestantism defended, clarified and codified over the course of a century and a half. The Reformation is incomplete without its confessional and doctrinal codification. What is more, Protestantism could hardly have survived if it had not developed, in the era of orthodoxy, a normative and defensible body of doctrine consisting of a confessional foundation and systematic elaboration.
Muller, Richard A.: Post-Reformation Reformed Dogmatics: The Rise and Development of Reformed Orthodoxy; Volume 1: Prolegomena to Theology. 2nd ed. Grand Rapids, MI : Baker Academic, 2003, S. 27