The devil—styled by Calvin as 'God's adversary and ours'—is ubiquitous in the witness of the New Testament. Yet contemporary Christian doctrine generally remains dumbfounded about what to do with him. At the same time, our present is marked by a resurgence in the language of the 'demonic'—that is, invocation of pervasive, radical, and perhaps personified evil. In light of this perplexity, Philip G. Ziegler asks pointedly: Can the gospel actually be heard and understood without meaningful reference to this inimical entity? Ziegler presents certain motivations we might have for revisiting the concept of the diabolical as a first step toward a Reformed doctrine of the infernal. Starting with an exhumation of the origins of our religious and cultural reticence about the devil, this study ventures a new diabology grounded in the witness of the Gospels. The identity and activities of the devil are discerned concretely in their manifold contradiction of Christ as the 'Way, the Truth and the