|If only one Gospel reports a story, does that make it suspicious?|
Our focus here is to counter the “argument against silence”, which is often used in an attempt to question or deny the veracity of what is, or is not, recorded in the Bible:
Applied to the NT, this is often used against Matthew's report of an earthquake and resurrected saints (which we will use as a template for the rest of this article), or John's lack of mention of the darkness at the crucifixion, or expanded, to any event of unusual nature reported by only one writer (like many of John's sign-miracles). The argument is also often extended to secular sources, and lack of a record among other persons, a matter that Glenn Miller has addressed here and which we have also touched upon here; see our analysis of responses to this here.
Just making such a claim, though, is not enough. One must actually name preserved sources and explain why they ought to have mentioned a certain event, not merely vaguely claim that it "ought to" have been preserved elsewhere (for an example of this exercised in practice, see here).
Let's discuss some factors related to this historical "silence" in terms of a modern perspective.
First: Few people in the ancient world were literate -- in fact less than 10% were literate to the extent needed to write documents (as opposed to, for example, people literate enough only to sign their names). Many published documents, like the Roman Acta Diurna, were read aloud by the literate to the non-literate majority, which, by itself cuts down the number of possible written witnesses to any event.
Second: Few ancient works are preserved to this day, which again cuts down the number of written witnesses available to us.
Third: Persons outside Jesus' social ingroup would not want or care to preserve the events of Jesus' life orally. They would not be transmitted and collected by the general public of that age -- ancient people were of a collectivist nature such that their main concern was their own group. Beyond this, as Miller points out, ideological enemies would be unlikely to keep such tradition alive, and would instead wish to dishonor the subject by aiding in the "dying out" of any honoring oral tradition.
See for example here to understand this in terms of an honor-shame dialectic, and why a Josephus or a Tacitus would not record such things as the feeding of the 5000, even if they did happen to think it was a true story.
Since we are working with the quake and saints of Matthew (hereafter, QS for short) as a template, let's set that down:
Matthew 27:51-53 And, behold, the veil of the temple was rent in twain from the top to the bottom; **and the earth did quake, and the rocks rent; And the graves were opened; and many bodies of the saints which slept arose, And came out of the graves after his resurrection, and went into the holy city, and appeared unto many.**
That the events framed by ** are not found in any other Gospel is the root of the argument encapsulated above. Surely, if this had happened (as the argument goes), wouldn’t Mark, Luke and John also have recorded such events in their record?
We reply that this is no more than a misinformed argument from silence. A historicity of the quake and saints may be suggested on other grounds, but we shall see that the silence of the other writers is not one of them.
Assumption #1: All the returns are in.
Central to this assumption is that such an event as the QS could not have been missed by the other Gospels if it had really happened, which is presumptuous. There is far too much we do not know about the QS to assume that it could not possibly have been missed. Glenn Miller has made some of these points, and we add some of our own:
We do not know:
By itself, this is enough to dismiss silence in parallel writers as problematic. It could be regarded as odd for these things to be omitted, but the answer is still, "Yes, but what of it?" There are, however, a few more things we can consider.
Assumption #2 -- They Would Have Made Room
John 21:25 And there are also many other things which Jesus did, the which, if they should be written every one, I suppose that even the world itself could not contain the books that should be written.
It does not take much to see that each Gospel writer does include things that are unique. Some of these are non-spectacular events, but both Luke and John are alone in reporting certain miraculous events, especially John.
Does this raise doubts as to their veracity? Why should Matthew, Mark and Luke have omitted the Cana water-to-wine miracle or the raising of Lazarus? Why should John have missed out on the raising of Jairus' daughter?
We could multiply these examples and for each note that we have some (or all) of the same questions as we do above. But let's just assume for the sake of argument that all the information of this sort in the four Gospels was available to all four authors to report. How then could they have missed reporting any of it?
The answer to this may be found in two social sub-factors:
The quote of John above is hyperbolic, but it does make a point. The ministry of Jesus lasted at least two years (for a defense of this point see here). This allows for a ministry of around 4000-5000 hours (take out time to sleep, eat, travel, etc.), which any writer of a life of Jesus had to select from.
If you were asked to write a biography of Jesus, what would you write about? Before you answer, there are some restrictions you need to keep in mind.
First of all, you are limited to using only about 20 sheets of paper.
What, you say? No more than that? No. Office Depot won't be open for another 1900 years, and neither will Wal-Mart, or Costco or any other place you are thinking of buying paper.
You're also not going to be writing on paper. You'll be writing on a scroll, and scrolls are both expensive and go no larger than a certain size. As Gamble reports in Books and Readers in the Early Church [44-50, 266], and Achtemeier in his JBL article, "Omne Verbatim Sonat"[11f]:
Now, maybe if you are wealthy, or know someone who is, you can get another scroll and do a "Life of Jesus, Part 2" (perhaps a shorter half), but if you do, bear in mind that generations beyond you (and how can you anticipate WalMart, or the printing press?), in order to preserve your work, will have to also buy two scrolls. If you want your work to get out to people, that's not a very smart move.
Your work is going to cost more to keep around than a work with one scroll, so you'd better plan carefully what you want to put on those scrolls.
By the way, writing is cumbersome and difficult with comfortable chairs and writings desks not in the picture -- unless, again, you are very wealthy. So, better keep it simple. (See more on this issue here.)
Okay, so now you have scrolls and some ink. Are you ready?
Not so fast! Did you ever have to write an essay of exactly a certain number of pages? No more or less than the decided amount? There should be no problem here with writing too little since Jesus did plenty of stuff, was around enough time and did enough teaching to draw plenty of material from. But you're only going to be able to fit a certain amount on those scrolls.
So, think for a while. What is more important to write about? His crucifixion and resurrection already have to go in there; that was the defining time in his life, and it is the heart of the kerygma.
What else? The miracles? The teachings? His birth? You have to decide what you want to present, and how, before you ever put a pen to that scroll. Bear in mind if you don't do this carefully, you'll waste the entire scroll and either have to buy a new one, or will have to cut out the sheet you made the mistake on and connect it all back together. Small mistakes can be fixed, but if you start to do a whole story, you can't just change your mind and start over!
And there's another problem. The crucifixion and resurrection have to go in, but they will be at the end of the story, and you can't just write backwards from the end of the scroll. So you need to plan this account carefully. You need to decide what out of those 5000 hours you want to include, in advance.
So how do you start? You start by taking notes, and this was the normal procedure for composition in that day. A Mark or a Luke will not have been an "exception" -- there was none. Eventually, this is where the "codex" or leaf book would have come in. Although the codex eventually evolved into the modern book, at this stage, according to scholars like Gamble, it was used for "school exercises, accounts, notes, first-drafts and so forth" as well as being used for archival items like birth certificates.
These loose notes would NOT be taken on the scroll intended for the composition but would be put on scraps of whatever was handy, or on a reusable wax tablet or wooden board.
So, now you have a collection of notes that are full of stories and teachings to choose from. Now what?
Well, if you are an ancient writer, writing a story is not just a matter of putting down things in order. You also want to establish a certain theme, or use certain techniques to make the story run smoothly (biographies in the ancient world were often written topically rather than chronologically).
After all, most of your "readers" will actually be hearers. 90-95% of those who get acquainted with your Gospel will have to remember its contents. Your contemporaries all have good memories, because they are used to oral tradition, but that's partly because writers know ways to make memory easier.
Our Gospel writers took different approaches to this problem. On a macro level, Matthew divided his work into five sections of teaching interspersed with miracle stories (an imitation of the five books of the Pentateuch) and also beginning with a genealogy and closing with an edict (the Great Commission), just like Chronicles opened with a genealogy and closed with Cyrus' decree in 2 Chronicles.
Mark used his "sandwich" technique of intercalating a small story between two parts of another story. Luke wrote his work around the theme of traveling to Jerusalem (and wrote Acts around the theme of the gospel being preached around the Empire, with Jerusalem as a return point); he was also writing for the purpose of defending Paul at trial (see here). John built his account around important "signs".
These are but three of numerous examples of memory and/or literary techniques in the Gospels -- and each technique, used differently, would mean different results in order, and different results in selection of material.
But, what of that selection? If you are a Matthew or a Mark writing a Gospel for the first time, what do you choose to offer? What miracles or teachings "stick out" the most and will tell readers the most about Jesus as a person? What events were most memorable?
By now it will be easy to guess that the constraints of selection would have a major impact on what appears in a Gospel and would explain a great many of the differences across the Gospels. In some cases, selection will be subjective. Selection will also be ruled by available space. Matters of judgment being subjective, this is why a Mark may prefer to offer two loaves and fishes routines, while Matthew may prefer to add more teaching instead.
On this matter as well, we have further input from Byrskog's Story as History concerning the selectivity of ancient historians in their reports. [256f] The rhetoriticians, as writers, "knew that certain matters had better not be included. One should avoid an excess of unnecessary facts and words, Cicero says. Other rhetoriticians said very much the same."
Further: "As a matter of course, a selection always took place on different levels of research and writing, such as when the historian chose what particular subject to investigate or when circumstances forced him to leave out matters concerning which he could not receive sufficient information."
Matthew alone may have had access to needed information in his time and place when he composed his gospel; so likewise Luke or even John. Each writer had to also consider their audience and decide what was "worth mentioning". We even see writers occasionally apologizing for including what they think may be perceived as unworthy information -- and needless to say, we, not being the intended audience, are in no position to make such a decision.
A good secular example should refute the argument that some event was "too important" to leave out:
As we see perhaps most evidently in the case of Xenophon, the essential criterion of this kind of selectivity remained quite subjective...the Hellenica Oxyrhychia, according to the London papyrus P. Oxy. 842 III 11-43, gives great prominence to the naval war of 396 BCE, while Xenophon mentions only the stir caused at Sparta in the winter of 397-396, ignoring entirely the war itself. An event that was extremely important for the Oxyrhynchus historian was not at all important for Xenophon. 
One can easily imagine critics arguing that this particular naval battle must not have happened if Xenophon said nothing about it. Pointing to other naval battles at other times mentioned would not resolve this point, any more than I would resolve the lack of mention of the saints by pointing to the mention of the raising of Lazarus.
A key issue Byrskog notes is that the historian was supposed to interpret and report history so as to make it a bridge between the past and the present.  Material was selected for relevance to the readership, not "because it was so exciting and amazing," and the resurrected saints were certainly of little relevance to anyone outside of Matthew's region in Syria and among Palestine Jews.
And then, what of later writers? A Luke or a John, knowing of or seeing an earlier Gospel, is also working with the same constraints you are in terms of expense and materials. So, why waste space reporting mostly the same things? Aside from the expected "defining moments" of the crucifixion and resurrection week, we would expect a later writer to try to select as many different events, not found in other Gospels, as possible, assuming he is aware of the writing of other Gospels (which we say, of course, Mark and Matthew are not).
And of course this is why John is so much different than the rest, generally speaking, and why he does not mention such things as the crucifixion darkness. He has another story to tell. In fact, he assumes you already know Mark (see here).
And so what of that particular example of the missing earthquake and saints (QS)? Even if we assume that Mark, Luke and John knew of these things, if they had other stories to tell, it is enough to point out that, practically speaking, they had no room to tell every detail. Luke offers instead some stories of resurrection appearances, and from his rushed ending apparently barely squeezed those in.
Now, which is more important? A story of the Risen Jesus, or a story of an earthquake (probably felt by few people, and definitely not felt by Luke's Gentile readers living outside Palestine) and some resurrected persons (who none of Luke's Gentile readers would have seen, and few others would have seen?)
Note that there is not a clear comparison here with such events as were recorded: the darkness or the rending of the Temple veil. These were events of public note and exposure; the quake likely was not, and the saints definitely were not, other than to some of Matthew's Jewish readers.
"But it's just a sentence! Surely Mark or Luke or John could have fit it in."
Sure! At the expense of some other part of their account being shorter or even omitted. Bear in mind that this little blurb about QS is part of the very end of Jesus' life, which is already very crowded at the end of the scroll. We do not know how Mark originally ended, and we see that John supplements the Synoptics; but that extra sentence for Luke (assuming he knew about the QS) means something else has to go.
How about, "And they gave him a piece of a broiled fish, and of an honeycomb"? Well, what about the need to stress the physicality of Jesus' resurrection body (very important in a Greco-Roman world that did not like the concept of resurrection)?
How about cutting out the repentance of the one thief (23:40)? Why do that for your sake? Another of Luke's themes is the universality of the Gospel message, and showing how even a despised thief could be saved illustrated that beautifully.
How about cutting the description of John the Baptist's garments? This was needed to tie John to the foretold Elijah of Malachi, and the fulfillment of this critical OT passage was of equal if not greater importance to those for whom such fulfillments were critical.
In short: One must do more than list up examples of what was included from each Gospel, and ask why X was more important than the raised saints. Such arguments simply ascribe their own value of worth on the saints, and then wonder why John, et al do not share that same value judgment.
In conclusion: While critics may (and no doubt will) reject accounts like the QS on any number of grounds, the exclusion of the report from the other Gospels is not sufficient grounds for doing so.