The book is Crossan's reduction of the authentic sayings of Jesus (according to his hermeneutic), and the outgrowth of his rather magisterial study: The Historical Jesus: The Life of a Mediterranean Peasant. That book, of course, both presumes and establishes the historicity of Jesus of Nazareth. But in his prologue to The Essential Jesus, Crossan provides a succinct refutation to the claim that there is no evidence, outside the gospels, of this man's existence.
If no Christian had written anything about Jesus for the first hundred years after his death, we would still have two succinct accounts from those not counted among his followers. One account dates from the last decade of the first century and comes from the Jewish historian Flavius Josephus in his Jewish Antiquities 18.63:John Dominic Crossan,The Essential Jesus (HarperSanFrancisco 1994, pp. vi-vii)
"About this time there lived Jesus, a wise man. . . . For he was one who wrought surprising feats and was a teacher of such people as accept the truth gladly. He won over many Jews and many of the Greeks. . . . When Pilate, upon hearing him accused by men of the highest standing amongst us, had condemned him to be crucified, those who had in the firstplace come to love him did not give up their affection for him. . . . And the tribe of the Christians, so called after him, has still to this day not disappeared."
His description is carefully neutral or, at most, mildly critical. The text was both preserved and interpolated by Christian editors, but I cite it without their proposed improvements.
The next account dates from the first decades of the sec-ond century and comes from the pagan historian Cornelius Tacitus. Having told how a rumor blamed Nero for the disastrous fire that swept Rome in 64 C.E., he continues in Annals 15-44:
"Therefore to scotch the rumour, Nero substituted as culprits, and punished with the utmost refinements of cruelty, a class of men, loathed for their vices, whom the crowd styled Christians. Christus, the founder of the name, had undergone the death penalty in the reign of Tiberius, by sentence of the procurator Pontius Pilatus, and the pernicious superstition was checked for the moment, only to break out once more, not merely in Judaea, the home of the disease, but in the capital itself, where all things horrible or shameful in the wor1d collect and find a vogue."
Despite the differences between the studied impartiality of Josephus and the sneering partiality of Tacitus, they agree on three rather basic facts. First, there was some sort of a movement connected with Jesus. Second, he was executed by official authority presumably to stop the movement. Third, rather than being stopped, the movement continued to spread.
There remain, therefore, these three: movement, execution, continuation. But the greatest of these is continuation.
If, after all, it is all invention, it had to be invented by someone. It had to have a focal point, an origination, a beginning. Scholars have long stopped debating the existence of Jesus of Nazareth. Now they discuss the life he lead (Crossan's books are excellent on this point), and the words he actually said.
Just using this contra-historical oxymoron (demonstrated by the eminent late Oxford historian, James Parkes, The Conflict of the Church and the Synagogue) exposes your Christian-blinkered agenda--dependent upon 4th-century, gentile, Hellenist sources.
While scholars debate the provenance of the original accounts upon which the earliest extant (4th century, even fragments are post-135 C.E.), Roman gentile, Hellenist-redacted versions were based, there is not one fragment, not even one letter of the NT that derives DIRECTLY from the 1st-century Pharisee Jews who followed the Pharisee Ribi Yehoshua.
Historians like Parkes, et al., have demonstrated incontestably that 4th-century Roman Christianity was the 180° polar antithesis of 1st-century Judaism of ALL Pharisee Ribis. The earliest (post-135 C.E.) true Christians were viciously antinomian (ANTI-Torah), claiming to supersede and displace Torah, Judaism and ("spiritual) Israel and Jews. In soberest terms, ORIGINAL Christianity was anti-Torah from the start while DSS (viz., 4Q MMT) and ALL other Judaic documentation PROVE that ALL 1st-century Pharisees were PRO-Torah.
There is a mountain of historical Judaic information Christians have refused to deal with, at: www.netzarim.co.il (see, especially, their History Museum pages beginning with "30-99 C.E.").
Original Christianity = ANTI-Torah. Ribi Yehoshua and his Netzarim, like all other Pharisees, were PRO-Torah. Intractable contradiction.
Building a Roman image from Hellenist hearsay accounts, decades after the death of the 1st-century Pharisee Ribi, and after a forcible ouster, by Hellenist Roman gentiles, of his original Jewish followers (135 C.E., documented by Eusebius), based on writings of a Hellenist Jew excised as an apostate by the original Jewish followers (documented by Eusebius) is circular reasoning through gentile-Roman Hellenist lenses.
What the historical Pharisee Ribi taught is found not in the hearsay accounts of post-135 C.E. Hellenist Romans but, rather, in the Judaic descriptions of Pharisees and Pharisee Ribis of the period... in Dead Sea Scroll 4Q MMT (see Prof. Elisha Qimron), inter alia.
The question is, now that you've been informed, will you follow the authentic historical Pharisee Ribi? Or continue following the post-135 C.E. Roman-redacted antithesis—an idol?