Why are there no historical testimonies of miracles outside the Bible consistent with the New Testament? How come there are no extra-biblical writings that confirm the New Testament? Why didn’t more non-Christian historians of antiquity mention Jesus? Those who did, why didn’t they paint Jesus in the same manner consistent with the Christians who wrote the New Testament (NT) documents? One may be inclined to ask these questions with good intentions, but the origin of the issue assumes a gaping oversight on the part of the questioner, and the answers are actually implicit in the questions themselves. All we need to do is consider history in light of the way in which personal persuasions work themselves out. Whether we’re dealing with supernatural events witnessed by extra-biblical writers or with their own testimony of historical narratives surrounding Jesus of Nazareth, there is a problem with the expectation of any writing existing outside the Bible, conferring full agreement with the Bible.
The Bible was composed through a process, which included a historical assessment of the writings. Now, for the sake of argument, because we’re chiefly concerned with the historical merits of the NT, and not necessarily with the supernatural inspiration of God, we’re only going to be looking at the practical historical questions. No doubt, if one accepts the inspiration of Scripture (as I do), the questions dissipate quickly, as only those writings which were understood to be inspired were included in the NT canon.
The biblical canon was formed by a rigorous analysis of what comprised historical trustworthiness and divine inspiration. Those with a higher view of Scripture would, of course, see the inspiration in light of historical reliability, which happens not in a biblical vacuum, but finds reciprocation between external historical sources.
Now, if you pull various writings together, as was done with the NT, that happen to be demonstrably more trustworthy to fit within your requirements, which all in one way or another, speak of Jesus’ godhood, would you actually have documents that are outside of this grouping? Aside from a few heretical pieces, I don’t think it likely, because you’ve already compiled the compelling writings into one volume that can be identified by a single name, namely the Bible, or more specifically, in this case, the New Testament. I would speak of the NT not by its name, but more something like “the writings that comprise the NT.” Many people who don’t know much about the formulation of the NT (or OT for that matter) assume that the writers got together and wrote this out, more or less at the same time and in the same place. Many actually believe that only one person was responsible for writing it. It helps to point out that there were multiple writers, writing at different times and places, many of whom would not have had access to each other necessarily. In that sense, the writings are independent accounts. I would think it positively absurd for there to be any reliable writing outside the Bible that speaks to the godhood of Jesus simply because all that was persuasive and demonstrated by its content to be worthy of inclusion was already included as part of the anthology of historical narratives, epistles and the like.
This is by no means a perfect analogy, but imagine a comprehensive effort of compiling all the information that’s known about quantum physics into one volume. Now, imagine asking for other information about quantum physics outside of that book? Is that reasonable? And if at some point, more information was revealed through science about quantum physics that met the high scrutiny and guidelines set forth, it would be added to the volume, right? So, in a sense, you will never truly have anything outside the anthology because everything that meets the guidelines would be added to the one volume.
Now, if all the biblical writings that comprise the Bible were determined to be reliable to be included in the set, would not the possibility of the existence of any extra-biblical writings be unlikely? Of course. At most, what we would expect to find would be later writings with third-hand mentions of events and people, namely Jesus, which we should not expect to always give us a view of Jesus consistent with the true heart of the message of the NT writings. And this is precisely what we have – people writings about Jesus, Christianity, and Christians who do not have favorable views. They simply write how they see the events in question peripherally, and what they think of Jesus and Christians, which is often very hostile and unfavorable. So, outside of a few historical factoids, should one expect any extra-biblical material to corroborate what is in the NT documents in its core message?
For more information and details about why early Christian testimony should be accepted as evidence and why it is erroneous to reject miracles through precedence see those respective articles as well.