In 2007 Joseph Ratzinger/Pope Benedict XVI published the first volume of Jesus of Nazareth not just as a devotional book, a "personal search for the face of the Lord", but as one written in conformity with "the historical-critical method". Scholars of this school treat the gospels as ancient literature and investigate them linguistically, historically and doctrinally in the cultural context of their age. The first volume did not really follow these rules: it was devoid of philological analysis and shied away from comparing contradictory statements, such as whether the gospels were intended only for the lost sheep of Israel or for the world at large. We were offered an old-fashioned story in which the gospels were taken quasi-literally and interpreted not in their historical framework, but in light of any passage picked ad lib from the Old and New Testament or from two millennia of Christian thought. It represented biblical exegesis as it was practised in the pre-modern era.

The volume provoked, in the pope's words, a "predictable variety of reactions". The chorus of approval by the pious was accompanied by scholarly voices of protest. The critics took exception to the book's rejection of the principal finding of the historical-critical school: the distinction between the Jesus of history and the Christ of faith. Ratzinger, they asserted, followed methodological rules only if they suited his theological preconceptions. I was curious to see part two, which had to deal with the tricky topics of the Passion and Resurrection. Not surprisingly, the general tone remains unchanged: it continues as an extended sermon. To detect, therefore, whether he shows any awareness of problematic issues, one must look at the pope's treatment of the conflicting chronologies of the Passion in the synoptic gospels (Mark, Matthew and Luke) and in John.

The facts are these. In the synoptics the last supper is a Passover meal eaten after sunset, when the Jewish day starts, on 15th Nisan. Everything that follows  Jesus's arrest, his trial and sentencing to death for blasphemy by the Jewish high court, his transfer to Pilate on the different charge of sedition, and the Roman proceedings leading to the crucifixion  occurs on the Passover festival. Yet the chief priests, sticklers for legal minutiae, spend the whole night and day engaged in forbidden activities on a feast day.

John, by contrast, antedates everything by 24 hours. The last supper is not a Passover dinner. There is no Jewish blasphemy trial; Jesus is simply interrogated by the former high priest Annas. In the morning, without the accused being present, the chief priests convene and decide to deliver the revolutionary Jesus to Pilate early on 14th Nisan. They refuse to enter the palace so as not to be defiled and barred from eating the Passover meal that evening.

Any historian familiar with Judaism must realise that the synoptic timetable is impossible: Jesus's two trials and crucifixion could not have taken place on Passover day. Obliged to make a critical choice, the pope judges the synoptic chronology erroneous and opts correctly for that of the fourth gospel. However, he wants to have it both ways. Instead of adopting the coherent story from John's gospel, he transfers the synoptic details that are missing from John, including the Jewish trial, to the day before Passover. But taking such liberties turns out to be costly: the denial of the last supper's paschal character flatly contradicts the clear mention of the feast in the synoptics and, further, clashes with the reference that Jesus and his party had sung the halleluiah psalms, "the hymn" concluding the Passover dinner, before they departed to Gethsemane.

A tougher challenge soon follows. Who is to be blamed for the death of Jesus? A decree of the Second Vatican Council prevents the pope from following 19 centuries of Catholic tradition and pointing the finger at the Jews. So what about Matthew 27:25, which states that, after asking for the release of Barabbas, "the people as a whole" shouted the fateful words, "His blood be on us and on our children"? Here the pope displays courage for a Christian leader of his disposition and correctly concedes that what Matthew reports is not a "historical fact": the whole Jewish people, he argues, could not have foregathered outside Pilate's residence. The exoneration of the Jews from the crime of deicide thus receives papal approval: the guilt lies, he declares, with the temple aristocracy and the pro-Barabbas mob. Legally, in fact, the chief culprit was Pilate, the notoriously cruel and lawless Roman governor, who was later dismissed from office and sent to Rome to account for his crimes.

One should add that the pope spoils the effect of his denial of general Jewish guilt for the crucifixion of Jesus by explaining the verse in Matthew as a "theological etiology"  an anticipated justification by Matthew of the terrible fate and total destruction the Jews brought on themselves by demanding Christ's execution.

Another quiet admission lurks in the evaluation of the resurrection testimonies. In a theologically mysterious way, the pope defines the resurrection as "a historical event that bursts open the dimensions of history and transcends it . . . the last and highest evolutionary leap". The evidence, he says, is twofold: confessional (the apostles and Paul profess that Jesus was resurrected) and narrative (the reports of the empty tomb and apparitions). For him the confessional traditions are certain, whereas the narrative testimony (on which, I would suggest, the confessions rely) is "not binding in every detail". In scholarly language this means that the records do not tally and are sometimes irreconcilable.

The pope's treatment of "the figure and the words of the Lord" consists of mountains of pious and largely familiar musings. He provides unquestioning Christians with plenty of solace. But today's many disturbed seekers after religious truth  people who long for fresh knowledge, inspiration and intellectual stimulus  had better look elsewhere for spiritual help. Gospel experts, however, may note with pleasure that 200 years of labour has not been in vain and that small fragments of New Testament criticism seem to have penetrated the mighty stronghold of traditional Christianity.

Geza Vermes is professor emeritus of Jewish studies at Oxford.