What is theology?
One traditional understanding of the term is "faith seeking understanding." For Ratzinger, theology begins where the human intellect, while important, is not sufficient. Theology is not meant for academic theologians alone, but for everyone. For Catholic theology to retain its character, its Catholicity, and not to merely comprise the content of any theologian's own thoughts, the Church and her Magisterium are necessary safeguards.
As one reviewer put it, a book like this is not a devotional manual. Joseph Ratzinger wrote a good deal, and some of his work can be more accessible than others, depending on what it is and the audience (his general audiences and encyclicals, for example, are more accessible than, say, the likes of Introduction to Christianity or The Spirit of the Liturgy). That said, what Ratzinger has always been about is the "why" of the Catholic faith-- in other words, what undergirds, focuses, and ultimately guides any devotion or prayer unto its proper end.