When Dave Armstrong was an Evangelical, he professed and preached the notion that the Bible is the only infallible, authoritative source of Christian faith and practice. Today, as a Catholic convert and apologist, he knows that disproving sola scriptura and answering the question of authority – of where we can be assured of finding authentic Christian truth – is the indispensable key to explaining and defending the Catholic faith.
He contrasts the Protestant’s “Bible alone” concept of authority – which, ironically, cannot be found in Scripture itself – with the Catholic “three-legged stool” of Scripture, Sacred Tradition, and the magisterium. Only the Catholic understanding, he shows, fully harmonizes with the Bible’s teachings on authority and provides a guide by which Christians can distinguish God’s revealed truths from the false traditions of men. Only the Catholic understanding can spare Christ’s Body the countless schisms that inevitably occur when Christians resort to private interpretation of God’s written word.