Action-provoking article from CT.
The reason Christians need to read The Hermeneutics of Doctrine is because of Thiselton's argument that, properly understood, doctrine involves the disposition of belief, which always includes formation and leads on to transformation. Each doctrine he examines, whether he says so with clarity or not, maps how these three terms are at work. In so doing, Thiselton reminds us that any piece of theology that does not lead to worship, absorption of God's work on the cross of Christ, and sanctity in life in community, is not genuine theology.
What does it mean to "believe" a doctrine as true? Belief, as Thiselton has learned from H. H. Price, is an utterance that is "inextricably embodied in patterns of habit, commitment, and action, which constitute endorsement, 'backing,' or 'surroundings' for the utterance." To "believe" is to take a stand in the face of opposition. He quotes Price: "If circumstances were to arise in which it made a practical difference whether p was true or false, he [the believer] would act as if it were true." To believe is "performatory" in character. Thiselton puts it like this: "Belief, then, is action-orientated, situation-related, and embodied in the particularities and contingencies of everyday living." He adds one more component, which, if he's right, shapes everything he says and everything we believe: belief in a doctrine involves "communal commitment and communal formation."
Or, as an old professor of mine named Robert Traina would say: You do what you believe, and you believe what you do.