VATICAN CITY — Since his election in April 2005, Pope Benedict XVI has spent almost all of his spare time at work on his new book. And now, after much anticipation, Jesus of Nazareth has been published.

The book’s central message: that Christ must be understood as the Son of God on a divine mission, not as a mere moralist or social reformer.

Reemphasizing Christ’s divine nature is especially important in a world that tends to ridicule religious faith and that is experiencing a “global poisoning of the spiritual climate,” the Pope explains in the book.

While Christ did not bring a blueprint for social progress, he did bring a new vision based on love that challenges the evils of today’s world — from the brutality of totalitarian regimes to the “cruelty of capitalism,” the Holy Father says.

The 448-page book was presented in its Italian, German and Polish editions at the Vatican April 13 and went on sale three days later, on the Pope’s 80th birthday.

The book will be published in 18 other languages, with the English edition available in mid-May. Italian publisher Rizzoli, which has had an initial print run of 350,000 copies, expects the book to sell swiftly.

Jesus of Nazareth is the first of two volumes on Christ’s life that Benedict intends to write. It covers the public acts of Jesus from his baptism in the Jordan River to the transfiguration before his disciples.

The book’s 10 chapters analyze Scriptural passages and also explore commentary from early Church Fathers and modern scholars.

He began writing the book in 2003, completed the first four chapters in 2004, and then finished the final six in his spare moments as Pope.

Benedict stresses that the book is not to be read as a magisterial document. Instead, it is an “expression of my personal seeking of the ‘Lord’s face,’” the Pope writes in the preface.

“Therefore, everyone has the liberty to contradict me,” the Pope says. “I only ask from women and men readers the anticipation of sympathy without which there is no possible understanding.”

Speaking at the Vatican book launch April 13, Cardinal Christoph Schönborn of Vienna noted that originally only “Joseph Ratzinger” was named as the author on the book’s cover.

“Just the simple believer, the Christian Joseph Ratzinger speaks here — not the Pope, not the former cardinal, bishop, professor, priest,” Cardinal Schönborn said.

A central theme of the Pope’s analysis is how in recent years Christ has been divided by biblical scholars into two figures: the “Christ of faith” and the “historical Jesus.” These “reconstructions” of Jesus, he argues, have diminished his divinity and ended up depicting Christ as simply one among many founders of religions.

The result is confusion, or worse. Such misinterpretations of the Bible can allow it to “in effect become an instrument of the Antichrist,” the Holy Father writes, by denying that God acts in human history.

Benedict insists that Christians must understand that the New Testament is more than a collection of symbolic or allegorical stories, and that it is not merely one of many myths of death and rebirth.

“Yes, it really happened,” the Pope writes. “Jesus is not a myth; he is a man of flesh and blood, a real presence in history. ... He died and rose again.”

Throughout the book, the Holy Father cites Old and New Testament passages to show that to understand Christ one must understand his “union with God the Father.” Only then, he asserts, do we have the right image of Christ and his vision, which can help bring social justice, particularly for the poor.

But more than a better world, what Christ brought to humanity was God himself, Benedict stresses. And in so doing, Jesus has communicated that God is close to people’s lives and is working in human history.

Speaking to the Register at the book’s launch, Cardinal José Saraiva Martins, prefect of the Congregation for the Causes of Saints, underlined the book’s contemporary relevance.

“Jesus was a teacher of doctrine and morals, but who does Christ represent today? Is he a concrete, existential figure?” he asked. “These are the questions we need to ask ourselves and this book, which is very challenging and profound, is very good for people of today, to know who Christ is for me, you and everyone.”

Another senior Vatican cardinal said Benedict’s book will lead people closer to Christ.

“My hope from this book is that people will love Jesus Christ, know him more, and by knowing him, will love him more,” said Cardinal Francis Arinze, prefect of the Congregation for Divine Worship. “And even if a particular person listening to us does not believe in Christ, let him read this book; it will do him good.”

Edward Pentin writes from Rome.

(CNS contributed to this report)