The intro to Peterson's latest book, The Jesus Way, functions like a good summary of a main theme in almost all of Peterson's writings, including those directed to pastors. He titles the intro "The Purification of Means" (via Maritain), the means, that is, of following Jesus. From the opening paragraphs:

"The ways Jesus goes about loving and saving the world are personal: nothing disembodied, nothing abstract, nothing impersonal. Incarnate, flesh and blood, relational, particular, local. The ways employed in our North American culture are conspicuously impersonal: programs, organizations, techniques, general guidelines, information detached from place. In matters of ways and means, the vocabulary of numbers is preferred over names, ideologies crowd out ideas, the gray fog of abstraction absorbs the sharp particularities of the recognizable face and the familiar street...We cannot use impersonal means to do or say a personal thing - and the gospel is personal or it is nothing....If any of the means we use to follow Jesus are extraneous to who we are in Jesus - detached 'things' or role 'models' - they detract from the end of following Jesus" (pp. 1-2).