Many scholars have used the writings of Josephus the Jew as historical
evidence for Jesus. But there are a lot of critics who say that the
writings of Josephus didn’t even exist until the sixth century. In other
words Josephus couldn’t have written it. What do you know about this?

I have not personally heard the sixth century date, but am aware of some
of the issues which have been brought up concerning Josephus’ writings.
That Josephus is a true person who wrote Histories for Roman emperors is
not in serious doubt. Serious scholars do not doubt that “The Jewish Wars”
and “Antiquities of the Jews” (his most famous works) were written by
Josephus.

Josephus, whose complete name was Joseph ben Matthias was born in AD 37
and died about AD 100. He was a Pharisee and a Jewish zealot. He fought on
the Jewish side in the wars with the Romans under Vespasian. He was
captured by the Romans at the fortress of Jotapata in AD 67. After his
capture, Josephus switched sides, actually becoming an adviser to
Vespasian and Titus when they attacked and eventually destroyed Jerusalem
in 70 AD. Josephus wrote his histories under imperial sponsorship. His
“Wars of the Jews” was published in about 78 AD. “Antiquities of the Jews”
was published in AD 93. Josephus published other works as well.

There is little doubt about the authenticity of his writings in general.
In fact, many Christian writers referred to Josephus and his writings long
before the sixth century date you mention. What there is some legitimate
doubt about is whether the manuscripts of his works might have been
tampered with, perhaps by early “Christian” writers. There is one
particularly interesting section in Antiquities 18:3:3 in which Josephus
describes Jesus as “a doer of wonderful works” and says concerning him,
“and when Pilate, at the suggestion of the principal men among us, had
condemned him to the cross, those who loved him at first did not forsake
him.” These passages clearly provide some support to the claims of
Christianity, and perhaps for this reason alone have caused some to wonder
if they are later interpolations of Christians into Josephus’ original
writings.

In summary, I am not sure exactly what you have heard, but it is fair to
say that the existence of Josephus and his writings in the first century
AD are not in doubt, but there is some debate about whether certain of his
writings may have been changed somewhat by others after his death.

John Oakes, PhD