This short book has been used by countless young people and adults to understand the basic concepts of the Christian faith. Its main use continues to be in classes for young people preparing to make their profession of faith or for adults who are beginning to commit to the Christian faith and its content. The book is an adaptation of the well-known Heidelberg Catechism, which is quite extensive. We are fully confident that this short book will continue to be a useful tool for the spiritual and cognitive formation of many believers in Christ.