@Olivier5,
In the case of Jesus, the case of his 'manhood' is buttressed by three independent sources: NT, Josephus and the Talmud.
And finally, according to Tacitus, Christians in Rome are a well established and identified group separate from the Jews by 64, the year of the great fire when Nero allegedly accused and persecuted the Christians of Rome for it. In fact, Tacitus even mentions the historical Jesus (not by name, only a certain 'Chritus':
"Consequently, to get rid of the report, Nero fastened the guilt and inflicted the most exquisite tortures on a class hated for their abominations, called Christians by the populace. Christus, from whom the name had its origin, suffered the extreme penalty during the reign of Tiberius at the hands of one of our procurators, Pontius Pilatus, and a most mischievous superstition, thus checked for the moment, again broke out not only in Judæa, the first source of the evil, but even in Rome, where all things hideous and shameful from every part of the world find their centre and become popular. Accordingly, an arrest was first made of all who pleaded guilty; then, upon their information, an immense multitude was convicted, not so much of the crime of firing the city, as of hatred against mankind".
(Annals 15.44)
The writing is on the wall.