I shall discuss three possible ways to account for them: (1) they are the result of chance; or (2) the “Josephus” passage is actually a later Christian interpolation influenced by Luke; or (3), the most interesting possibility, Josephus and Luke both based their descriptions on statements circulated by Jewish Christians during the years 80-90 C.E.
8 Concluding Remarks and Two SpeculationsThe coincidences occurring between Josephus’ description of Jesus and that found in the Emmaus narrative have not been previously appreciated. Those I have discussed fall into three classes:
(a) Detailed structural coincidences, beginning with the initial vocabulary cluster, that form a shared outline not found in comparable texts of the era;
(b) Coincidences at difficult textual points, the most peculiar being the participial form of the ”third day,” unique in, respectively, Josephus and Christian literature. Other points examined were a rare first person usage, and the presentation
and terseness concerning Jesus’ deeds, the predictions of the prophets, and the sentencing.
(c) Coincidences with the Arabic version of the Testimonium, which was shown to be, at the most critical points, more similar to the Emmaus narrative than it was to the received Greek version of the Testimonium.
Three explanations for these coincidences have been considered.
(1) They could be due to chance. But this would seem to gainsay the three independent forms of evidence listed above. In particular, it is difficult to ignore that the only two known examples of the ”third day” as a participial phrase appears in texts with so many other structural resemblances. Some common literary milieu seems mandatory; the question is the form it took.
(2) The coincidences may be due to a Christian interpolator who altered the Testimonium, or forged it entire, under the influence of the Emmaus narrative. This proposal has the weakness of supposing that a writer capable of imitating Josephus’ style* and daring enough to alter his manuscript would at the same time employ non-Josephan expressions and adhere rather closely to a New Testament text. A forger of the required skill should have been able to shake free of such influences.
(3) Josephus and Luke may have used similar or identical sources in composing their passages. This explanation appears to be the simplest. It not only explains the series of coincidences, but it also goes a long way toward solving a number of mysteries that have bothered commentators of the Testimonium...
http://www.josephus.org/GoldbergJosephusLuke1995.pdf