This one can only be charitably be described as "way out there." It does have the endorsement of a credentialed scholar or two; albeit, those who are also regarded as "out there" by their peers (e.g., Robert Eisenman). This is the sort of thing peer-reviewed periodicals like the Journal of Roman Studies would never print.
So what's the theme? I'll lay it out in three categories, noting Atwill's most notable and signifcant failures in each case:
The Roman Piso theory...
Caesar's Messiah is like this theory in terms of conspiracy-mindedness, viewing Christianity as an invention of the Roman establishment for a purpose. It does exceed the credibility of the Piso theory by a razor-thin margin, inasmuch as it at least uses real people rather than inventing them out of nothing but semantics.
But the virtues over the Piso theory stop there. This time, rather than the non-existent Piso family, it is the Emperor Titus who is said to be the inventor of Christianity. His goal was to create a "peaceful Messiah" figure for those rebellious Jews to follow, as a way of pacifying them; the joke being, that they would actually be worshipping Titus himself, unawares (more on this below).
In on the conspiracy as well was Josephus, a client of the Flavian family of which Titus was a member, and who left clues in his works for later and more clever discerners.
After 73 AD, when Rome had finished defeating the Jews, "someone" from within a circle of the Flavians (Titus, Vespasian, etc.), the Herods, and the Alexanders decided they could "tame messianic Judaism" by transforming it into a religion that would "cooperate with the Roman Empire."  The system and its documents were written after the war was over; that includes the material attributed to Paul [211f].
So now we have a description; let's talk about errors:
- A chief impetus for this idea, Atwill says , was that he could not conceive of how Judaism could produce two movements so diametrically opposed as the warlike Sicarii and the "peace"-advocting Jesus.
Atwill's conception, unfortunately, lacks a certain perspective; one may as well ask how early 20th century African-American society could have produced both a Malcolm X and a Martin Luther King.
The clue missed is that Jesus' message was not one of peace, but of a sword, as he himself said -- the Gospel message undermined the values then held current, via subtle influence rather than direct force as the Sicarii preferred. If Atwill cannot see that Jesus' message was not indeed, at its core, hostile to Roman php and society in terms of the components it offered, then he needs to do some more research (see here).
- Furthermore, it is clear that Atwill fails on the point of ancient social psychology. He supposes that Jesus was invented to attract militaristic, messianic Jews; yet the figure of Jesus is precisely what a dedicated Sicarii would least follow. Jesus would be regarded as being as far out of the ingroup as could be conceived; he would even be taken by the Sicarii as a disgrace to YHWH.
Indeed, Atwill openly contradicts himself, for he claims he cannot see how Judaism could produce such diametric opposites, yet he argues that Christianity was built to make these opposites attract. He supposes, in other words, that Judaism would not produce such a group; but he hypothesizes that Jews then converted to such a group.
Yet that is unreasonable even in truth, for such rebels would not approve of Jesus even as we know him; the positive view of tax collectors, Roman officials, etc. that Atwill sees would have been exceptionally repugnant to the very people being targeted. The idea that Christianity was intended to prevent the spread of messianic Judaism to the provinces  ignores the fact that Jews of the Diaspora were Hellenized enough that they did not support such a movement in the first place (the misplaced hopes of the rebels, recorded by Josephus , notwithstanding).
Atwill cannot have his cake and eat it too. In addition, the idea he sees in Paul and Josephus that "the Romans were God's servants" finds its roots in OT indications that punishers like the Assyrians and Babylonians were doing God's will -- and finds no particular favor for the Romans.
- One also wonders why in the world Titus would care to start a new religion for Jews that he had already soundly beaten on the battlefield. One also wonders how and why a mission to the Gentiles got started; indeed, why Titus would allow his own "Frankenstein's monster" to get loose onto persons with whom he had no problems of loyalty.
- Even more problematic for Atwill is what is said by Roman writers whose works he ignores. Tacitus' comment in Annals 15.44 places the origins of Christianity, and Roman reaction to it, nearly a decade before Titus' final victory. Atwill says nothing at all about this critical passage; nor does he mention Pliny's letter to Trajan asking what to do about Christians.
Atwill wishes to posit convenient forgetfulness as the cause of the loss of knowledge about Christian origins; and how credible is it that Hadrian and Pliny "forgot" this, or did not know about it? How credible is it that Domitian (himself a Flavian) persecuted Christianity and forgot that his own relatives had created it in the first place? Why would some of those relatives actually become Christians?
Atwill makes no effort to explain how Christianity spread; he offers a single paragraph on this saying that "wicked priests" introduced the religion to the masses (Jewish?); but then, "The first people to hear the story of Jesus would most likely have been slaves (Gentiles???) whose patrons simply ordered them to attend services. After a while some began to believe, then many."  End of explanation.
....meets Randel Helms' Gospel Fictions....
Atwill appeals to the use of "typology" by the Flavians -- who learned the technique from Judaism -- as evidence of Christianity's Flavian origins. The claim that the Flavians had to borrow "typology" is wrong to begin with; even the ancient pagans thought in terms of probabilities (prior recurring themes and actions) so there was no need to borrow the idea from Judaism. Otherwise, Atwill assumes, as Helms does, that use of typology proves wholesale invention; and that claim we have refuted in the linked article.
It is linked as well with Atwill this his third aspect:
...meets Dennis Ronald MacDonald's The Homeric Epics and the Gospel of Mark. No, there's no thesis of Homer being copied here; but Atwill uses some of the same principles as HEGM to make its own case.
One chapter early on is devoted to finding parallels between Jesus' recruitment of disciples to be "fishers of men" and Titus' campaign on the Sea of Galilee. The prime comparison speaks for itself as unreasonable: Atwill parallels Jesus' "become fishers of men" statement to the Roman act of dispatching Jews who had fallen into the sea during a naval battle by hitting them with darts or cutting off their hands -- thus becoming "fishers of men" because the Romans "caught like fish" the Jews in the lake. It is hard to say how one "fishes" men being killed and allowed to sink and drown. For Atwill, it is proof enough to stretch the point to make this "grim comedy" .
It gets no better, as Atwill stretches between Matt and Luke for the two phrases associated with the fishers of men story by each, "do not be afraid" and "follow me," and makes it into a parallel of Josephus reporting how Titus not saying these words, no; but telling his men not to desert him (but rather, implicitly, follow him) into battle.
And more, as Atwill hops around Matthew and Luke ranfomly, turning a mention by Josephus of a "Coracin fish" as a parallel to a condemnation of the city of Chorazain in Matthew 11:23, nowhere near the "fishers of men" story. The city's name means "smoking furnace" and has nothing to do with fish.
In a second story, Atwill draws a connection between a Mary in Josephus (see more on this below) and the one in the NT; namely, that the former is said to be "pierced through her very bowels and marrow" because of hunger, while the latter is to be "pierced through your own soul" (Luke 2:35) because of grief over her son's death. His rationale that "soul" and "bowels" are synonymous does not work for it is merely a tenuous, contrived connection of the same type above, making soldiers who kill men in the water with darts and swords into "fishers".
Those who need as reminder of how this sort of theorizing can be misused are reminded that it is just as easy to do the same elsewhere, as for example we did with Lincoln and Kennedy. When there are no constraints, as there are when Atwill operates, any such connection can be made.
His further appeal to the former Mary's roasting and eating of her infant son as a "blackly comic"  type of the Passover lamb (!), and describing that child as a "sacrifice," speaks for itself as a distortion of concepts as well as of the English language.
Atwill also cannot understand how it is that the eating of this infant would prompt this Mary to say, "Come on; be thou my food, and be thou a fury to these seditious varlets, and a by-word to the world, which is all that is now wanting to complete the calamities of us Jews." He finds in this a lampoon, in which Christ is the one to "complete the calamity."
More informed scholars find in this an allusion to the Deuteronomic (28:53) warnings of cannibalism as a curse of the Jews for disobedience, one of many "calamities" to befall them, and perhaps one of the last yet fallen upon Jews being besieged in Jerusalem, and also a sign to the "varlets" (the Jewish rebels) who were the root cause of the siege, and hence her own drive to cannibalism.
A score of Atwill's errors are the result of not recognizing (as MacDonald did, though less often) that some commonality reflects a commonplace. The use of spittle by both Jesus and Vespasian to heal an illness  reflects then-current perceptions that a holy man's spittle had healing properties -- not a unique point of contact between Jesus and Vespasian. (Atwill also omits how Vespasian healed a man's withered arm, by stomping on it -- which finds no parallel with Jesus.)
But perhaps his largest error of this sort (and overall) is finding commonality in names. He marvels that there was a "Jesus" who preached and a "Jesus" who also led rebels against Titus on the Sea of Galilee  -- oblivious to the point that (as we have heard so much about, related to the "James ossuary") "Jesus" was as common a name for Jews of that period as "Bob" is for men today. He makes the same error concerning "Mary" (a name held by up to a third and at least a fourth of Jewish women of this era; thus, despite Atwill, there is no oddity in two sisters having variations of that same name , and his argument that the Romans turned "Mary" into a "nickname for female rebels"  is shown erroneous). And the same error is made with "Simon." Atwill did no checking into this subject beyond the list of Biblical names in a chart from Webster's  and so errs badly when he declares how unlikely it is that the NT and Josephus would record so many Jewish people with the same names.
Like MacDonald, Atwill also freely roams all over the texts to make his tenuous connections. He treats the Gospels as a uniform whole (in other words, the conspiracy is assumed in order to prove it) so that, for example, he pulls the use of the word "Gethsemane" from Mark and combines it with Jesus' bloody sweat (mentioned only in Luke) to create a whole parallel  to what are also two separate stories in Josephus.
This methodology is explained as part of the whole scheme that only Atwill has been able to discover, a scheme that "kept the comedy from being too obvious" other than to "readers alert enough to combine elements from different versions" and speaks as well of Atwill's magnified self-perception as it does of his creativity. As with MacDonald, Atwill is constrained to explain why generations of intelligent and credentialed scholars (he is, by the way, merely a "businessman") have missed these points for thousands of years. His explanations that everyone else has been unable, as he has, to "contradict a deeply ingrained belief"  and that their religious leanings have rendered their intellect "powerless"  to discern the truth speaks for itself in terms of what he must do to explain this, and it also speaks for itself that he must use the "apparent vagueness"  of the alleged parallels as a supposed proof of the validity of his thesis.
Finally, let's note some of Atwill's most peculiar errors:
- It is claimed that the church's "structures of authority, its sacraments, its college of bishops, the title of the head of the religion, the supreme pontiff-- were all based on Roman, not Judaic traditions." [20-1].
This is partly false, partly misleading. The advanced structure of pontiff and college did not exist until much later, when indeed, Roman influence abounded (Atwill is mistaken to ascribe the title of "pope" to men as early as Clement I ; it was not used as a title for one man until St. Siricus in 384).
It was also not until much later that Rome was chosen as the church's headquarters, despite being also the center of persecution (with Jerusalem destroyed, Rome is no more an odd choice than New York would be today). The authority structures and sacraments, however, mirror the Jewish synagogue -- and a universal structure of everything from religions to fireman's clubs, which had communal meals and organizational structure built on the same basic model.
Atwill also misuses Clement's letter to Corinth, which does not say anything about the "church's authority structure...resembling the Roman military" but rather appeals to the universal virtue of order and discipline.
There are even more errors where Atwill's use of the popes is concerned. He hints at malfeasance in that Irenaeus names the "sixth" pope Sixtus; it would not occur to him that the one with the strained imagination was Sixtus himself, in choosing the name, not Irenaeus. He also says that the name of the third pope, Anacletus, means "irreproachable" and connects this to the letter to Timothy that says that a bishop must be "irreproachable"; he is confusing anegkletos ("irreproachable") with anacletos ("called forth, invoked").
- The question is asked , "...how did a religion that began as verbal traditions in Hebrew or Aramaic change into one whose surviving Scripture is written almost entirely in Greek?"
Aside from neglecting scholarship that finds Semitic roots behind NT texts (though no doubt the Flavians did convenient research to ensure this?), it ignores the point that expressing its texts in the lingua franca of the day (Koine Greek) is exactly what we would expect from a missionary faith. It is a better question why Titus published in Greek material that was intended to target people who mainly spoke Aramaic and Hebrew.
- Atwill misreads  Jesus' prophecy as saying a "Son of Man would come to Judea...encircle Jerusalem with a wall, and then destroy the temple..." No prophecy of Jesus says that "the Son of Man" would do these acts; they are corollary acts to the enthronement of the Son of Man in heaven, and thus Atwill's claim that Titus "fulfilled" and identified himself with the Son of Man is gravely in error.
- There is the standard error reading Matt. 27:24 as anti-Semitic .
- Atwill makes much of Titus using the word "repent" as Jesus did. The word itself is used dozens of times in the Old Testament; and the theme itself is all over the OT, and no doubt it and its permutations appear in other secular works.
But Atwill claims, "Jesus never gives an answer to the question" of "exactly what sin does he wish the Jews to repent of" .
What sin? Does Atwill suppose that Jesus is supposed to be walking around with a list of every particular and unique sin every person has committed and announcing them to each person one at a time? The obvious answer to the question is, "whatever sin you have done".
- The same error concerning "Immanuel"  that Miller has answered here.
- The standard error concerning Zachariah and Berechiah , used for Atwill's purposes, as he explains away the lack of match to what is said by Jesus (in terms of the exact name and location) as part of the way of obscuring the joke.
- Atwill uses the invented Pope Leo X "fable" quote though he somehow manages to attribute it not to Leo, but to Cesare Borgia, the son of Pope Alexander VI (who was 10 years before Leo). No source is cited for this attribution.
- Atwill carelessly attributes the words of John the Baptist to Jesus .
In the end, creativity is Atwill's most-used method, and the number of props and contrivances he must use to hold up his theory, undoes his credibility as a researcher. Atwill again and again says that this or that point in the NT is some sort of "joke" or "satire" on some historical event concerning Titus. The method is epistemically useless because it is unfalsifiable; Atwill is also inevitably unable to explain why the jokes are actually funny. As subjective as humor is, Atwill's mere word that X was "funny" to the Flavians rings hollow.
His further claims that the histories of both Josephus AND the Gospels were "fictitious"  bespeak a writer of the sort who would rather believe that Jesus had an unknown evil twin who faked his Resurrection appearances than accept that the Resurrection actually occurred.
I recently found a “response” to this review, by Atwill. It took Atwill several years, apparently, to get up the gumption to make a reply, although to be fair, it may have been delayed because he was spending so much time looking for scholarly credibility, which is always in short supply for any theory for which it is required that one purse their lips and wear ruby slippers to make it believeable.
To begin, Atwill accuses me of “straw men” which is generally codespeak in Skeptical language for “he said something that devastated my thesis, so I’ll parse what I said so that it seems to the already convinced in my readership like I said something different.” In particular, he cites my words:
It is clear that Atwill fails on the point of ancient social psychology. He supposes that Jesus was invented to attract militaristic, messianic Jews; yet the figure of Jesus is precisely what a dedicated Sicarii would least follow. Jesus would be regarded as being as far out of the ingroup as could be conceived; he would even be taken by the Sicarii as a disgrace to YHWH. Indeed, Atwill openly contradicts himself, for he claims he cannot see how Judaism could produce such diametric opposites, yet he argues that Christianity was built to make these opposites attract. He supposes, in other words, that Judaism would not produce such a group; but he hypothesizes that Jews then converted to such a group.
Of course, I never claimed Christianity was invented to convert the Sicarii zealots in Judea, an absurd idea. I wrote that the religion was designed to be a theological barrier to prevent the spread of the militarized messianic movement to Jews living throughout the empire.
Um – what exactly is a “militarized messianic movement” if the Sicarii are not? Or, by extension, Jews with the same sentiments? Please note that I gave the same general category Atwill just did in his response (“militaristic, messianic Jews”) and then narrowed to the group called the Sicarii as a particular example given by Atwill, as I noted in the review:
A chief impetus for this idea, Atwill says , was that he could not conceive of how Judaism could produce two movements so diametrically opposed as the warlike Sicarii and the "peace"-advocting Jesus.
So Atwill is clearly trying to divert from his outstanding failure to address the far more critical point concerning ancient social psychology, of which, he knows absolutely nothing (e.g., the mechanics of honor and shame, collectivist mentality, and so on), and which render his thesis manifestly foolish.
Atwill then rambles over to what he calls “errors of fact” starting with where I said:
The idea that Christianity was intended to prevent the spread of messianic Judaism to the provinces ignores the fact that Jews of the Diaspora were Hellenized enough that they did not support such a movement in the first place (the misplaced hopes of the rebels, recorded by Josephus, notwithstanding).
Atwill deems this false, and calls upon Wikipedia (!) for proof to the contrary, but he isn’t paying attention very well. His reference is to the Kitos War, which occurred 115-117 AD, but he is ignoring the fact that he has this setup precisely backwards when he appeals to it. The Kitos War was a reaction to the injustice which started in 70 AD when Rome trashed Judaea. In contrast, what I am referring to is the alleged introduction of Christianity by the Romans (as Atwill so foolishly theorizes) at a much earlier date than the Kitos War, and THAT time is my frame of reference for my comment that “that Jews of the Diaspora were Hellenized enough that they did not support such a movement in the first place”. My reference to Josephus should have made this clear to even someone as poorly educated as Atwill, but apparently this is what it took Atwill all those years to come up with.
My review was several pages long, but Atwill can do no better than find one more alleged “error”:
Holding also factually misstates the condition of the messianic movement immediately after the war, He wrote:
“One also wonders why in the world Titus would care to start a new religion for Jews that he had already soundly beaten on the battlefield.” In fact, immediately after Titus had put down the rebellion in Judea another messianic rebellion broke out in Alexandria. (See Josephus, Wars of the Jews, 7, 10)
Is this supposed to be meaningful? It isn’t. By destroying the Temple, Titus had won the war; it signified that God had abandoned the Jews. Atwill also conspicuously fails to tell his readers that what Josephus refers to is disturbances in Alexandria that were instigated by Sicarii who had fled to Jerusalem after being beaten there. So in reality, this was nothing more than a mop-up after the decisive victory – and I might add, still no reason for Titus to invent a religion for them, since he beat them soundly there as well.
In the next section I am accused of “conceptual myopia” for not graciously submitting to Atwill’s insane parallelomania. He can call them “obvious connections” until he is blue in the face, but they are still nothing but manufactured and contrived. I pointed out:
One chapter early on is devoted to finding parallels between Jesus’ recruitment of disciples to be ‘fishers of men’ and Titus’ campaign on the Sea of Galilee. The prime comparison speaks for itself as unreasonable: Atwill parallels Jesus’ ‘become fishers of men’ statement to the Roman act of dispatching Jews who had fallen into the sea during a naval battle by hitting them with darts or cutting off their hands — thus becoming ‘fishers of men’ because the Romans ‘caught like fish’ the Jews in the lake. It is hard to say how one ‘fishes’ men being killed and allowed to sink and drown.
Atwill petulantly responds then when fishing, one usually kills the fish, but if he wants to strain that far, I’d like to know where the Romans also scaled, broiled, and ate the men they attacked. He also points out that some of the men swam to safety, but last I checked, fish can’t do that, much less escape to safety on the shore, where they will die. It speaks for itself that Atwill ignores my extended methodological critique (including the linked criticisms of similar efforts by Helms and MacDonald, and my parody referring to Lincoln and Kennedy) and instead spends almost a page repeating the stories he naively thinks are parallels, so that the reader can decide (and knowing full well the uncritical reader he seeks will already decide in his favor).
I also noted:
His further appeal to the former Mary’s roasting and eating of her infant son as a ‘blackly comic’ type of the Passover lamb (!), and describing that child as a ‘sacrifice,’ speaks for itself as a distortion of concepts as well as of the English language.
Atwill calls my response “ridiculous...because the ‘human Passover lamb’ in Josephus was so designated in the exact same manner that the authors of the Gospels used to designate Jesus as a Passover lamb. The cannibalized child was referred to as the “roasted sacrifice” of the “house of Hyssop”. Thus – like Jesus – the child was designated a human Passover by stating that he was a “sacrifice” and then combining “hyssop” with one of the instructions for the preparing of the Passover sacrifice.
Well, I hate to break the bad news to Atwill, but Jesus is nowhere referred to as a “roasted sacrifice” of the “house of Hyssop.” He is not even referred to in terms of the Passover, save in Paul (not the Gospels), and by straining meaning to the breaking point and misusing the use of “sacrifice” language applied to Jesus ( a point I discuss in detail in a chapter in The Atonement Contextualized). Jesus is not a “human Passover” at all.
Beyond that, Josephus says the child was “roasted” but does not call him a “roasted sacrifice” – it perhaps does not occur to Atwill that roasting was simply the most convenient and available form of cooking for that period – and where Josephus uses the other phrase is, “There was a certain woman that dwelt beyond Jordan, her name was Mary; her father was Eleazar, of the village Bethezob, which signifies the house of Hyssop.” Clearly Atwill is straining here; and he can do no more than appeal to someone else who makes the same strained interpretation beyond that.
In a final section Atwill alleges a “blunder” with respect to this:
Atwill misreads Jesus’ prophecy as saying a ‘Son of Man would come to Judea...encircle Jerusalem with a wall, and then destroy the temple…’ No prophecy of Jesus says that ‘the Son of Man’ would do these acts; they are corollary acts to the enthronement of the Son of Man in heaven, and thus Atwill’s claim that Titus ‘fulfilled’ and identified himself with the Son of Man is gravely in error.
In reply he merely quotes the texts again, but he is missing my point badly because he is utterly ignorant of my views on eschatology, and also because he is missing the point of my criticism, which is to respond to his absurd notion that the texts predict the Son of Man personally destroying the Temple. The texts Atwill quotes in Luke and Mark do not say this. He also could stand a primer in the real meaning of the “visitation”. I alluded to my preterist views, and he claims that they are “not an idea that can even be responded to in the rational context.” No doubt – because Atwill is simply grossly ignorant of my views and my extended defenses of them, and would at any rate be incapable of responding to them even if he were aware of them.
Secondarily, Atwill replies that it is “factually incorrect” that Titus identified himself as the Son of Man, but what he produces in reply isn’t anything showing that Titus made messianic claims of himself, but that others did, which is not what I said. Atwill would help himself tremendously if he actually got the criticisms right. I might add that the messianic claims are not the sum of the claims made of the Danielic Son of Man – we are still wondering where Titus assumed a throne in heaven in all of this.
That’s all Atwill has to say, but we would like to know about his other errors and problems with his thesis. He ignored 98% of what I pinned him for above, including his embarrassing use of the "Christ a fable" quote.
Perhaps he will have an answer in another 50 years.