I'm continuing a discussion with Jon Curry on some issues related to early church history in another thread. Some subjects have come up there that I think warrant some attention in a post of their own. I want to address three points.
Jon has brought up Irenaeus' false belief about the age of Jesus. He uses that mistake as a justification for dismissing Irenaeus' testimony about the authorship of the gospels. I've discussed some of the reasons why Jon's argument is fallacious in that other thread, but I want to emphasize, here, one of the points I made in that thread. There is no early document that explicitly tells us that Jesus was such-and-such an age when He died. We arrive at conclusions about His probable age by means of putting together various pieces of information. We today may think that it's obvious that Jesus died in His 30s, since we hear that conclusion so often from pastors, historians, etc., and we so often see artwork, movies, and such that portray Jesus as somebody in that age range. But whether Jesus was in His 30s or 40s isn't of much significance to Christianity, and Irenaeus lived at a time when that issue hadn't received nearly as much attention as it has since then. As I explain in the other thread, it seems likely that Irenaeus reached his false conclusion based primarily on a misreading of John 8:57 and perhaps some other data. When he refers to elders of the church confirming what he was reporting, those elders probably only confirmed the historicity of John 8:57, an oral tradition related to some other passage of scripture, or something else that Irenaeus wrongly associated with Jesus' having lived to an old age. If those elders had taught that Jesus lived so long, it seems unlikely that so many other early sources would disagree with Irenaeus on the point. Irenaeus did make a mistake that he attributed, in part, to the traditions of the elders, but it was a mistake on a subject that's somewhat difficult to discern and about which Irenaeus didn't have nearly as much easy access to information as we have today.
Secondly, we ought to keep in mind that it's common for historical sources to be mistaken on some subjects. I remember seeing a television program on Josephus while I was in college. The program gave examples of issues where historians rejected Josephus' claims, yet the program went on to mention how Josephus is trusted on other issues. Similarly, witnesses in a court of law often are mistaken in many areas of their lives. One man may read his horoscope every day, another man may not remember his anniversary date, and another may have some false beliefs about American history. It wouldn't make sense for a defense attorney to try to undermine these three men's testimony about a crime they witnessed by mentioning their lack of credibility on the issues I just referred to. Tacitus was a Roman historian who sometimes had potential motives to make an emperor or Rome in general appear better than they actually were, but we can't therefore dismiss everything he reports on such subjects.
J.P. Holding has a good article on the gospels that I recommend reading. He writes the following after discussing the evidence for Tacitus and the works attributed to him:
"Comparably speaking, this evidence [for Tacitus] is vanishingly small compared to the incredible number of attestations and attributions by patristic writers [for the gospels], some few earlier than (but many as late as) those listed for Tacitus above. How can someone dealing with the evidence fairly claim to be sure of Tacitus' authorship of his various works (where such external evidence is concerned) and dismiss the Gospels, which have far better external evidence? I have recently checked a book titled Texts and Tranmission (Clarendon Press, 1993) which records similar data for other ancient works. Throughout the book classic works from around the time of the NT whose authorship and date no one questions (though some have textual issues, just like the NT) are recorded as having the earliest copy between 5th and 9th century, earliest attributions at the same period (for example, Celsus' De medicina is attested no earlier than 990 AD, and then not again until 1300!), and having so little textual support that if they were treated as the NT is, all of antiquity would be reduced to a blank wall of paranoid unknowingness. If the Gospels are treated consistenly, there will be no question at all about their provenance, but that is clearly the last thing critics want to do."
Craig Keener, commenting on attempts to deny that the same author wrote the gospel of John and the Johannine epistles, writes:
"No other author of antiquity could survive the nit-picking distinctions on which NT [New Testament] scholars, poring over a smaller corpus, often thrive. As a translator of Euripides for the Loeb series notes, Euripides’ ‘plays, produced at times widely apart, and not in the order of the story, sometimes present situations (as in Hecuba, Daughters of Troy, and Helen) mutually exclusive, the poet not having followed the same legend throughout the series.’ He would not fare well in the hands of our discipline." (The Gospel Of John: A Commentary, Vol. 1 [Peabody, Massachusetts: Hendrickson Publishers, 2003], p. 125)
D.A. Carson and Douglas Moo, after addressing the external evidence for John's authorship of the fourth gospel, write:
"Most historians of antiquity, other than New Testament scholars, could not so easily set aside evidence as plentiful and as uniform." (An Introduction To The New Testament [Grand Rapids, Michigan: Zondervan, 2005], p. 233)
The double standard isn't just a result of a distinction between religious and non-religious literature. As Martin Hengel notes:
"Thus we have only one biography of Muhammad (who died in 632), by Ibn Hisham (who died in 834, 212 years after the Hijra), which has incorporated parts of the lost earlier biography by Ibn Ishaq (died 767). Although the chronological distance from the historical subject in the Muhammad biography is much greater [than it is with Jesus], the historical scepticism of critical European scholarship is substantially less here." (The Four Gospels And The One Gospel of Jesus Christ [Harrisburg, Pennsylvania: Trinity Press International, 2000], p. 6)
People aren't threatened by the writings of men like Tacitus, Euripides, and Ibn Hisham as much as they are by the New Testament documents. Double standards are applied.
In closing, I want to comment on one other subject. Jon Curry has referred to Tertullian as a "vicious" and "wicked" man, and he recently suggested that Irenaeus was "lying". I think that when a person gets to the point of denying Jesus' existence and describing men like Irenaeus and Tertullian as vicious and wicked and liars, he's probably crossed the line from healthy skepticism to unhealthy skepticism.