Carotta believes that Flavius Josephus created the cult of Jesus based on the cult of Julius Caesar. Josephus took on the pseudonym Paul and wrote the Pauline epistles of the New Testament, and his disciples wrote the gospels. The source for their literary creations was primarily the now-lost Historiae of Asinius Pollio. Carotta's book points out some interesting parallels between the gospels and various Roman histories about Caesar. Some of them may well suggest literary dependence of some sort, but the reader is forced to wade through an incredible amount of bombast and just plain silliness to find isolated nuggets of information worthy of serious consideration.
Throughout, the author displays the quasi-religious fervor of a true-believer who has absolute knowledge of absolute truth and despises anyone else who cannot see it. For example:
"The results of this investigation are not a matter of debate anyway, and being objective facts cannot be argued away. Just as the earth does not stop rotating on its axis simply because the Church had such trouble getting along with Galileo or because we continue to speak romantically of sunsets, Jesus does not stop being Divus Iulius simply because obscurantists today, once again, do not want it to be true ... " (p.14)
I know of no reputable historian who would make statements like this. History is always a matter of interpretation and probabilities, and the minute one assumes absolute knowledge of "the truth" one becomes blind to evidence that might point in other directions. One finds only what one wants and expects to find.
Carotta assumes that if the early Christian authors did any copying of Roman literature they must have exclusively copied and transformed Roman literature. Once again, reality is not quite that black and white. If some of the parallels seem convincing, that only indicates the likelihood that Christian writers used some Roman literature as models. They also used other literary models, such as the Hebrew Bible. Crafting a fictional story about someone's life does not mean the person himself must be fictional, any more than the fictional story about chopping down a cherry tree means George Washington himself was fictional or a literary mirror image of, say, King George.
While some of the parallels Carotta points out are striking, most of them are contrived at best. A fairly typical example of his methodology:
"Since _metanoias_, `of repentance,' looks very similar to _Metellus_ [the name of Pompei's father-in-law], and _baptisma_ is near _postulatio_, `demand,' as well as _kerysson_, `preaching,' is not far from _Caesar_, then _kai kerysson baptisma metanoias eis aphesin (h)amartion_ would stand for _a Caesare postulabat Metellus dimissionem armorum._ In English, `and preaching a baptism of repentance for the remission of sins' would simply stand for `Metellus demanded from Caesar the dismissal of his army.'" (p.178)
Using this kind of methodology I could probably prove that Paul cribbed most of Dr. Seuss's book _Green Eggs and Ham_ while writing his epistle to the Romans.
The author has read little of modern historical and scriptural scholarship. For example, I know of no current biblical scholars who would date Mark to "40-60 AD" or who would argue that it was translated from Latin. He cites no source for the former and cites works from 1893 and 1926 for the latter. He does not know Hebrew (see p.53) and so misses many obvious cases where words came from Hebrew rather than by means of some torturous transformation and metathesis from Latin.
Nevertheless, there are a few insightful needles hidden in this haystack of a book. For example, Carotta proposes that Joseph of Arimathea is a stand-in for Josephus himself, pointing out that Josephus' original name (before he took the Roman name Flavius) was "bar Matthias" (son of Matthias). No place named Arimathea is attested anywhere else in ancient literature, and there is indeed a remarkable resemblance to "bar Matthias." Even without citing this similarity in names, another biblical scholar already proposed a similar interpretation: see Paul Tarazi, New Testament: An Introduction: Luke and Acts (New Testament Introduction), p.178-179. For Tarazi, however, Joseph of Arimathea is a negative figure in the gospel story, in effect a put-down of Josephus; while for Carotta, Joseph of Arimathea and Josephus are supremely positive figures because Josephus is ultimately the very author of the story.