The religious understanding of most Christians today and for the immediate future depends on the priests and ministers in parishes and schools. Theologically and sociologically, given their professional training and official commitment, they constitute an obvious centre in deepening and renewing, perhaps even revolutionizing, the Christian's grasp of the word of God. But developments in modern theology have proceeded so rapidly that even the professional finds it difficult to keep apace. What of the priest, or the brother, sister or layman who seeks understanding of these developments?