Ratzinger, one of the key persons responsible for the compilation of the Catechism of the Catholic Church, offers new insights on the catechetical character and Biblical foundation of the worldwide bestselling Catechism that has had such a positive response from ordinary Catholics across the globe. But he acknowledges that the response of many theologians and "professional religionists" has been negative toward the Catechism.

He says that if theologians don't want to be "shut out" of this worldwide development of sensus fidei and lose touch with the common Catholic, they will have to engage the Catechism positively. The main purpose of this book is to offer an invitation to this changed approach to the Catechism. He wants people to see, as he shows here, how the Catechism is an excellent teaching tool that responds to man's deepest questions about the meaning of life, how to live a good life, and how to attain happiness in this life and in eternal life. He shows how the Catechism affirms that man's happiness is love, and that the essence of true love has been manifested in the Person of Jesus Christ.