Over the last few decades, Christian apologetic defenses of the historicity of the New Testament have typically pursued a minimal facts approach according to which one seeks to establish a basic set of core claims about the life and death of Jesus which are most widely accepted by biblical scholars (e.g. crucifixion; empty tomb; post-resurrection appearances). One then argues that the resurrection is the best hypothesis to explain those commonly agreed upon facts.
The minimal facts approach is helpful for justifying a basic commitment to the most important historical claims of Christian faith. On the downside, it offers no defense of the historical veracity of vast portions of the New Testament.
The fact is that there are other apologetic strategies which offer a more robust historical defense of the New Testament documents. And in her new book Hidden in Plain View, philosopher Lydia McGrew introduces one of those approaches. She calls it the argument from undesigned coincidences: rather than focus on minimal facts, it looks instead for evidence of broad historical reliability in New Testament documents based on the phenomenon of so-called undesigned coincidences.
The Concept of an Undesigned Coincidence
So what is an undesigned coincidence? Let's begin with a simple example. Imagine that there are two eyewitnesses to a robbery in a café. Notably, while Smith describes the thief as a very tall male, Jones does not mention the thief's height at all. However, Jones does mention in passing that as the thief ran out of the café, the hanging light fixture was left swinging.
That detail raises a question: what caused the light to swing? Since the thief would need to run underneath the light to exit the café, it is a reasonable supposition that his head brushed against it as he left. And given that the light is suspended 6'5" off the floor, that would imply that the killer was very tall. And so, Jones' seemingly irrelevant observation actually dovetails nicely with Smith's physical description of the thief.
The fit between Smith's and Jones' testimonies is notably different than if they had both simply described the thief as "very tall". For one thing, a simple agreement in testimony would be liable to the interpretation of collusion: if Smith and Jones had given identical statements, it is possible that they might have intentionally coordinated their reports. The fact that their testimonies differ supports the conclusion that they are indeed independent witnesses. And the fact that those testimonies also dovetail on the question of height suggests that they are both reliable witnesses of the same event.
With this in mind, here is McGrew's formal definition of the concept:
"An undesigned coincidence is a notable connection between two or more accounts or texts that doesn't seem to have been planned by the person or people giving the accounts. Despite their apparent independence, the items fit together like pieces of a puzzle." (12)
Just as an investigator looks for undesigned coincidences between testimonial witnesses as a means to corroborate the reliability of the witnesses, so McGrew points out we can evaluate the New Testament documents in like manner. Where differences may exist, she avers, they tend to be superficial: look deeper and one finds a reassuring connection between witnesses, often of a subtle, complex, and elegant sort which defies any easy dismissal as chance or collusion. Instead, the most plausible interpretation of these various examples is that we have independent and reliable witnesses of the purported events.
Two Examples of Undesigned Coincidences
Hidden in Plain View provides a survey of multiple such coincidences in the New Testament as part of a broad cumulative argument in favor of general historical reliability. The book consists of six chapters divided into two parts: Part One focuses on undesigned coincidences in the Gospels and Part Two focuses on undesigned coincidences between Acts and the Pauline Epistles. In this section, I will recount two examples from the Gospels that pertain to the same event, the feeding of the five thousand.
Example 1: The Green Grass (pp. 66-67)
McGrew points out that three Gospels mention the fact that the crowds sat down on grass. (This detail contrasts notably with the feeding of the four thousand which makes no reference to grass.) But only Mark observes that the grass was green(6:39). Why does this detail matter? Because grass is only green in that region in the spring just after the winter rains. Thus, that detail locates the miracle in the springtime.
Next, McGrew points out that the Gospel of John states that the miracle occurred at the time of Passover (John 6:4), and Passover occurs in the spring.
Note that neither Mark nor John directly states that the miracle occurred in spring. Rather, one says the miracle occurred when there was green grass and the other says the miracle occurred during Passover. But both of those details locate the event in the spring. McGrew observes, "here we have a perfect fit between John's casual reference to the time of year and Mark's specification of the detail of the green grass." (66)
Example 2: Why ask Philip? (pp. 107-110)
Our second example begins with Jesus asking Philip where they can buy bread to feed five thousand people (John 6:5). To be sure, McGrew points out that Jesus' question was not serious: he was simply setting up his anticipated miracle. Nonetheless, the question arises: why ask Philip in particular? After all, he was not one of the more prominent disciples (108).
The answer provides our second intriguing coincidence. McGrew observes that Luke places the feeding of the five thousand near the town of Bethsaida (Luke 9.10). Earlier in John 1:43-44 we learn that Philip is from Bethsaida (109). When we add these details together, we find a satisfactory answer to our "Why Philip?" question. Jesus directs his question to Philip because they are located near Philip's hometown. Again, we find an elegant answer to a question which indirectly confirms the accuracy of two different Gospels (Luke and John).
The green grass and Jesus' question to Philip are but two examples of such serendipitous coincidences: the book outlines close to fifty more connections between the Gospels, Acts, and the Pauline epistles. Some are simple but others are complex and nuanced. Add them together and one has a powerful cumulative case argument for the general reliability of the bulk of the New Testament documents.