Jspear said:Tertullian and Origen lived at just the same time as the philosophers you mentioned (alive earlier than a couple of the ones you mentioned) and they were Christians. Personally I think we can trust their writings over the work of Roman and Greek philosophers because this was more of their "field" of professionalism.
Here is an article on archaeology and the bible. There is more material evidence for the bible than any other book in antiquity.
https://answersingenesis.org/archaeology/does-archaeology-support-the-bible/
http://www.4truth.net/fourtruthpbbible.aspx?pageid=8589952738
Precisely because they were Christians, they were writing to discredit the people you claim to have no historical merit. But this is a bad, biased and generally unreliable historical approach, hence of poor quality.
Their value rather resides in allowing us to perceive the anti-social and transcendentalist Christian ethos at the time. Anti-social because under their narrow, vapid innocence, one detects the fierce intransigence of the sectarian who values himself above other men, and the voluntarily circumscribed vision of a self-appointed elect to be "saved"; transcendentalist because they believed in forms of life and thought which were in fact not their own, while, in shunning life, glorified virtues befitting of children and uneducated slaves at the expense of more virile and more intellectual qualities. Hence we find the reason behind Plutarch's castigation of all such superstitions that lulled the simple-minded, or the cowardly into their clutches.
In spite of their singularly flat prose, furthermore, one can nevertheless discern in these writters the appealing charm of virtues of simple folk, all which strongly resembled the fraternities and mysteria that slaves or poor citizens found almost everywhere in honor of the pagan gods in the crowded quarters of ancient Roman cities. (Plutarch's "states of opinion" to be combated).
Another apologist Quardratus even hoped to make a Christian of the emperor, assuredly striving to convince him of the excellence of his doctrine, and to prove, above all, that it offered no harm to the State. Yet any tolerance shown to these fanatics was immediately mistaken by them for sympathy for their cause. His work, now lost, though commented on by Eusebius' Ecclesiastical History, Book IV, was a defense of his religion about the life of a young prophet named Jesus who was the founder of the sect, but who died a victim of Jewish intolerance a century before. This young sage seems to have left behind some teachings not unlike those of Orpheus, to whom at times his disciples compared him. In it, too, as with Tertullian and Origen, were those scraps of wisdom ineptly borrowed from the works of the gentile philosophers. One speedily tires though of such captious arguments.