God's Word, according to Ratzinger, is encountered in the Bible, in tradition, and through the teaching office of the bishop, who, through apostolic succession, is to be the servant of and the witness to the divine Word. Ratzinger examines as well the relationship between the episcopacy and the papacy. He also considers the nature of apostolic succession, and he responds to objections to the Catholic view of the subject. His treatment is sympathetic to the concerns of non-Catholic Christians while remaining faithful to Catholic teaching and practice.

This book also includes the famous Erasmus Lecture of Cardinal Ratzinger, which assesses the strengths and weaknesses of modern critical approaches to biblical interpretation. Ratzinger proposes a new approach that avoids the pitfalls of a narrowly critical outlook on the Bible without succumbing to fundamentalism.

God's Word provides insights into Pope Benedict XVI's efforts to renew the Church's participation in God's Truth through the divine Word, as well as the Church's mission to proclaim the Word to all people.