Undesigned Coincidences

Summary

The Gospels, Acts, Paul's letters, and the Old Testament histories interlock in dozens of small, unplanned ways.  One account raises a question in passing.  A different account answers it in passing.  Neither author shows any sign of noticing.  This pattern is called an undesigned coincidence.  It is what real, independent testimony looks like.  It is not what legends, copying, or coordinated fiction look like.

Suppose Mary tells you little Billy has a black eye.  Susie separately tells you Billy tried to steal another kid's lunch money.  Neither girl mentions the other's detail.  But the two details snap together, and you can surmise what happened.  If Mary and Susie were inventing stories separately, their details would not fit.  If they were inventing a story together, they would tell you the connection instead of leaving you to find it.

This argument is old.  William Paley built a book on it in 1790, and John James Blunt extended it to the whole Bible in 1847.  Secular historians of that era used the same test on Homer, on Chinese antiquities, and on the Norman Conquest.  The argument was largely forgotten in the 20th century, then revived by philosopher Tim McGrew and analyzed book-length by his wife Lydia McGrew in 2017.

This article gives the strongest examples, then states the objections and their answers.  Some proposed coincidences are weak, and this article says so.

How the Argument Works

Lydia McGrew defines the term:  "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."¹

Three features give the argument its force:

1. Forgers don't hide their evidence. A faked connection only helps the forger if readers notice it. J.S. Howson made this point in 1877: "An intentional and contrived coincidence must be of such a character as to strike the reader. Otherwise it fails of its purpose. If it was kept latent for the intelligent … critics of a later age to find out, it has not attained the end for which it was meant at the time of its contrivance."²
2. Real witnesses produce this pattern. J. Warner Wallace, a cold-case homicide detective, writes: "True, reliable eyewitness accounts are never completely parallel and identical. Instead, they are different pieces of the same puzzle, unintentionally supporting and complementing each other to provide all the details related to what really happened."³
3. The argument is cumulative. Any single interlock could be luck. Dozens of them, spread across every part of the documents, could not. McGrew is candid that the examples vary in strength: "Some of the cases I will discuss are easier to explain away than others as sheer coincidence."¹

The flip side of the argument matters too.  The gospels differ in wording, order, and selection of details.  Skeptics read these differences as contradictions.  But identical accounts would prove collusion, not truth.  Paley made this point in 1794:  "The usual character of human testimony is substantial truth under circumstantial variety.  This is what the daily experience of courts of justice teaches...  a close and minute agreement induces the suspicion of confederacy and fraud."⁴

History of the Argument

William Paley, the Anglican philosopher best known for the watchmaker argument, coined the term and built the first book-length case in "Horae Paulinae" (1790).  He compared Acts with Paul's letters and argued that forgers do not plant clues no reader will notice:  "Coincidences so circuitous [indirect or roundabout] as this answer not the ends of forgery; are seldom, I believe, attempted by it."⁵  Paley made "undesignedness" the explicit test:  "In examining, therefore, the agreement between ancient writings, the character of truth and originality is undesignedness."⁵  He applied the method to the gospels in "A View of the Evidences of Christianity" (1794).¹

John James Blunt, Lady Margaret Professor of Divinity at Cambridge, extended the argument to the whole Bible.  His work, begun in an 1828 volume on the gospels, Acts, and Josephus, became the 1847 book "Undesigned Coincidences in the Writings Both of the Old and New Testament."⁶  Blunt threw down the challenge plainly:  "In our argument we defy people to sit down together, or transmit their writings one to another, and produce the like."⁶  The book sold steadily for decades — a third edition by 1850, an eighth by 1863, a thirteenth by 1876.⁶  Thomas Birks continued the project in 1850 with "Horae Apostolicae," appended to his edition of Paley.¹

The argument then fell out of use for over a century.  New Testament scholar Craig Keener calls it "a long-neglected consideration for the reliability of the Gospels and Acts" and offers a diagnosis:  "Probably a more influential factor in the neglect of the undesigned coincidences argument, at least in biblical studies, has been our appropriate but often myopic focus on single sources."⁷  Lydia McGrew's verdict on the older apologists:  "their arguments have been not so much refuted as forgotten in the shifts of theological fashion."¹

Lydia McGrew's husband, philosopher Tim McGrew of Western Michigan University, revived the argument in lectures and interviews beginning in 2011, followed by a six-part written series in 2013.⁸  It drew enough attention that Bart Ehrman debated Tim McGrew about it on British radio in 2015.⁹  His wife Lydia McGrew gave it a book-length treatment in 2017, "Hidden in Plain View," with a foreword by Keener,¹ and a formal probabilistic defense in the journal Erkenntnis.¹⁰  Jonathan McLatchie and Erik Manning have since defended and popularized it online.¹¹

Secular Historians Use the Same Argument

The test is not special pleading invented for the Bible.  Historians of the same era applied it to secular texts in the same words.

• Homer. William Gladstone — the four-time British prime minister and a serious Homer scholar — defended a disputed verse of the Odyssey this way in 1858: "The verse is therefore supported by something in the nature of a spontaneous or undesigned coincidence."¹²
• Chinese antiquities. Samuel Kidd, professor of Chinese at University College London, argued in 1841 that the Hieroglyphica's account of Chinese characters "harmonizes so clearly with certain treatises on the Chinese symbols, by learned natives… that this simple circumstance of undesigned coincidence pleads most powerfully for the genuineness of a large portion of the Hieroglyphica."¹³
• The Norman Conquest. Edward Freeman, Regius Professor of Modern History at Oxford, tracking Tostig's movements in 1066: "And, small as the point is, it is worth noticing as an undesigned coincidence that Orderic makes Tostig set sail from the Côtentin, while the English Chronicler makes him land in the Isle of Wight."¹⁴ Freeman later called an Anglo-Saxon Chronicle–Domesday Book interlock "one of the best examples of an undesigned coincidence" — and, in the same book, warned that the argument can misfire when handled carelessly.¹⁵
• Anthropology. E.B. Tylor, the founder of cultural anthropology, screened his ethnographic reports by "'the test of recurrence,' or of undesigned coincidence in testimony."¹⁶
• Modern cases. Luuk van de Weghe's "Living Footnotes in the Gospel of Luke" (2023) documents undesigned coincidences among the recollections of six women who witnessed Anne Frank's final months in the camps.¹⁷ Lydia McGrew has shown the same pattern in testimony from the 1948 Hiss-Chambers espionage case.¹⁸

Two more examples circulate in apologetics lists — Robert Latham on the Lombard migration and a Fortnightly Review note on the death of Phrynichus in Thucydides.  Attempts to verify these against the original scans failed, so this article does not use them.

In 2018 the argument itself passed peer review:  Lydia McGrew's "Undesigned Coincidences and Coherence for an Hypothesis" formalized its logic in the secular philosophy-of-science journal Erkenntnis.¹⁰

In the Gospels

Each example below is stated as "X explains Y":  the account being explained raises a question it never answers, and the explaining account answers it without noticing.

The Paired Disciples

Mark explains Matthew — Matthew 10:2-4 lists the twelve disciples two by two:  Peter and Andrew, James and John, Philip and Bartholomew, and so on.  Mark and Luke list the same names, but not in pairs.  Why does Matthew alone pair them?  Mark 6:7 says Jesus sent the disciples out "two by two."  Mark never gives the pairings.  Matthew never mentions that they were sent in pairs.¹

Herod's Remarks to His Servants

Luke explains Matthew — Matthew 14:1-2 records what Herod Antipas said privately "to his servants":  "This is John the Baptist; he has been raised from the dead."  How would Jesus' followers know table talk from inside Herod's court?  Luke 8:3 mentions, in a list of women who funded Jesus' ministry, "Joanna, the wife of Herod's steward Chuza."  Luke never explains why he names her husband's job.  Matthew never explains his court source.¹  Blunt added Acts 13:1, where one of the Antioch church leaders is Manaen, "a member of the court of Herod the ruler":  "We see, therefore, that Christ had followers from amongst the household of this very prince, and, accordingly, that Herod was very likely to discourse with his servants on a subject in which they were better informed than himself."⁶

Healing After Sunset

Mark and Luke explain Matthew — Matthew 8:16 says the people of Capernaum brought their sick to Jesus "that evening."  Why did they wait for evening?  Matthew doesn't say.  Mark 1:21 and Luke 4:31 note, in passing, that this day was a Sabbath.  Carrying the sick was forbidden work on the Sabbath, and the Sabbath ended at sunset.  Mark 1:32 even doubles the time marker — "that evening, at sunset" — the moment the Sabbath expired.

A caution:  Mark contains both halves of this one — the Sabbath and the sunset.  If Matthew copied Mark and dropped the Sabbath, no independent knowledge is needed.  Lydia McGrew excludes this example from her book for exactly that reason.¹  It carries weight only against the claim that Matthew wrote carelessly, not against copying.

The Green Grass

John explains Matthew and Mark — Mark 6:39 says the five thousand sat down "on the green grass."  Grass in that region is brown most of the year.  It is green in spring, after the winter rains.  John 6:4 supplies the date, for an unrelated reason:  "Now the Passover, the festival of the Jews, was near."  Passover falls in spring.¹  Blunt noticed the grass detail in 1847:  "the abundance of the grass was a feature of the scene of the miracle of the five thousand, which had impressed itself on the eye of the relator."⁶  At the feeding of the four thousand, a separate event at another time, the crowds sat "on the ground."  (Matthew 15:35, Mark 8:6)

Why Ask Philip?

Luke and John explain each other — At the feeding of the five thousand, John 6:5 says Jesus asked Philip where to buy bread.  Philip is a minor figure.  Why ask him?  John never says.  Luke 9:10 locates the event near Bethsaida.  John 1:44 — five chapters earlier, in an unrelated scene — says "Philip was from Bethsaida."  Jesus asked the local where to buy food.  The answer requires assembling three passages from two books.¹

Woe to Bethsaida

Luke explains Matthew — In Matthew 11:21 Jesus condemns Bethsaida:  "Woe to you, Bethsaida!  For if the deeds of power done in you had been done in Tyre and Sidon, they would have repented."  Matthew records no miracle at Bethsaida.  What deeds of power?  Luke 9:10-17 places the feeding of the five thousand there, and Mark 8:22-26 adds a blind man healed just outside the village.¹

Sons of Thunder

Luke explains Mark — Mark 3:17 says Jesus nicknamed James and John "Boanerges, that is, Sons of Thunder," and never says why.  Luke 9:54 shows the brothers asking, when a Samaritan village rejected Jesus:  "Lord, do you want us to command fire to come down from heaven and consume them?"  Luke never mentions the nickname.

Why Did Jesus Wash Feet?

Luke and John explain each other — John 13:4-5 says Jesus washed the disciples' feet at the last supper, but gives no occasion for it.  Luke 22:24 says that at that same supper "a dispute also arose among them as to which one of them was to be regarded as the greatest."  Jesus answers the dispute:  "the leader [must become] like one who serves...  But I am among you as one who serves."  (Luke 22:26-27)  Luke's "one who serves" saying, in turn, reads like a comment on an act Luke never records.  Each gospel preserves half of one scene.¹

"Am I Not to Drink the Cup?"

Matthew, Mark, and Luke explain John — At the arrest, Peter cuts off the ear of the high priest's servant.  Jesus stops him:  "Am I not to drink the cup that the Father has given me?"  (John 18:11)  John's gospel nowhere else uses "the cup" as a figure for the crucifixion.  The synoptics explain it.  An hour earlier in Gethsemane Jesus prayed, "remove this cup from me" (Mark 14:36, Matthew 26:39, Luke 22:42) — a prayer John does not record.  Months earlier Jesus had asked James and John, "Are you able to drink the cup that I drink?"  (Mark 10:38, Matthew 20:22)¹

"Are You the King of the Jews?"

Luke and John explain each other — In Matthew 27:11, Mark 15:2, and John 18:33, Pilate opens Jesus' trial by asking, "Are you the king of the Jews?"  None of the three explains where Pilate got that charge.  The priests' accusation in those gospels was blasphemy, a religious offense Rome didn't care about.  Luke 23:2 alone records the charge the priests actually brought to Pilate:  "We found this man perverting our nation, forbidding us to pay taxes to the emperor, and saying that he himself is the Messiah, a king."

The favor is returned.  In Luke 23:3-4, Pilate hears this charge of sedition, asks Jesus one question, and immediately announces:  "I find no basis for an accusation against this man."  Why so fast?  John 18:36-37 records the conversation Luke skips:  "My kingdom is not from this world.  If my kingdom were from this world, my followers would be fighting to keep me from being handed over."  Pilate concluded the man was no military threat.¹

Malchus' Ear

Luke explains John — At that trial Jesus tells Pilate his followers are not fighting (John 18:36).  But John 18:10 says Peter had maimed the high priest's servant, Malchus, hours earlier.  Couldn't the priests produce an earless servant to refute Jesus?  Luke 22:51 — the only gospel to record it — says Jesus "touched his ear and healed him."  There was no evidence left to produce.¹

Who Knew the Servant's Name?

John explains John — This coincidence runs between passages of a single gospel.  John 18:10 names the wounded servant:  Malchus.  John 18:26 knows more:  one of those questioning Peter in the courtyard was "a relative of the man whose ear Peter had cut off."  How would a Galilean fisherman's circle know the names and family ties of the high priest's household staff?  John 18:15-16 mentions, without connecting it to anything, that the disciple who got Peter into the courtyard "was known to the high priest."  The gospel never draws the line between these dots.  As the 19th-century lawyer Edmund Bennett put it, "Forgers do not rest content with such roundabout confirmations."¹

Pilate's Surprise

John explains Mark — Mark 15:44 says Pilate "wondered if he were already dead" and checked with the centurion before releasing the body.  Crucified men usually lingered for days.  Why was the centurion so sure?  John 19:33-34 explains without meaning to:  the soldiers, finding Jesus already dead, skipped breaking his legs, and one drove a spear into his side to make sure.  John never mentions Pilate's surprise.  Mark never mentions the spear.

Joseph of Arimathea's Courage

John explains Mark — Mark 15:43 says Joseph of Arimathea "went boldly" to Pilate to ask for Jesus' body.  Why did asking take boldness?  John 19:38 says Joseph "was a disciple of Jesus, though a secret one because of his fear of the Jews."  A secret sympathizer outing himself to claim a condemned man's corpse needed courage.  John doesn't mention the boldness.  Mark doesn't mention the secrecy.¹

A New Tomb

Matthew explains Luke and John — Luke 23:53 says Joseph buried Jesus in a tomb "where no one had ever been laid."  John 19:41-42 adds that it was new and conveniently nearby.  Where did Joseph get instant access to an unused tomb outside Jerusalem?  Matthew 27:59-60 says it was Joseph's own tomb, and that Joseph was rich.  Matthew, the tax collector who repeatedly notices money, is the one who supplies the financial detail.¹

"Do You Love Me More Than These?"

Matthew and Mark explain John — In John 21:15 the risen Jesus asks Peter, "Simon son of John, do you love me more than these?"  Why "more than these"?  Jesus elsewhere discouraged the disciples from comparing themselves.  Matthew 26:33 and Mark 14:29 record Peter's boast on the night of the arrest:  "Though all become deserters because of you, I will never desert you."  Peter had claimed a loyalty above the others', then denied Jesus three times.  John records the boast in different words (John 13:37) but not the comparison with the other disciples that Jesus' question echoes.¹

Between Acts and Paul's Letters

Paley's Horae Paulinae worked through these in 1790.  Acts and the letters were written for different purposes — one is a travel history, the others are pastoral correspondence — yet they mesh at the level of itineraries, names, and offhand grudges.

Mark, the Cousin of Barnabas

Colossians explains Acts — In Acts 15:37-39, Paul and Barnabas split up over John Mark, who had deserted them mid-journey (Acts 13:13).  Paul refused to take him again.  Barnabas insisted, and "the disagreement became so sharp that they parted company."  Why did Barnabas stake his partnership with Paul on this one unreliable assistant?  Colossians 4:10 mentions, in a greeting list:  "Mark the cousin of Barnabas."  Acts never mentions the kinship.  Colossians never mentions the quarrel.¹

Timothy's Circumcision

Acts and 2 Timothy explain each other — 2 Timothy 1:5 and 3:15 say Timothy was raised on the Jewish scriptures "from childhood" by a believing mother and grandmother, Eunice and Lois.  A son of a Jewish mother should have been circumcised in infancy.  Yet Acts 16:3 says Paul had the adult Timothy circumcised.  Acts 16:1 supplies the missing piece:  "his father was a Greek."  Acts also omits any mention of Timothy's scriptural upbringing, and the letters never mention the Greek father who plainly blocked the circumcision.¹

Paul's Persecutions

Acts explains 2 Timothy — Paul reminds Timothy of "my persecutions, and my suffering the things that happened to me in Antioch, Iconium, and Lystra."  (2 Timothy 3:11)  Paul was persecuted nearly everywhere.  Why pick those three towns for Timothy?  Acts 13-14 records the persecutions:  driven from Pisidian Antioch, nearly stoned at Iconium, actually stoned and left for dead at Lystra — in that geographic order.  Then Acts 16:1-2, describing Paul's next visit to the region, introduces "a disciple named Timothy" living there, already "well spoken of by the believers in Lystra and Iconium."  Timothy was a local convert from Paul's previous, violent visit.  Those three persecutions were the ones he had witnessed.  Paul also omits Derbe from the list — the one town on that route where Acts records no persecution.¹

"If Timothy Comes"

Acts explains 1 Corinthians — Paul writes, "If Timothy comes, see that he has nothing to fear among you."  (1 Corinthians 16:10)  Paul sent the letter, yet is unsure whether his own messenger will arrive?  Acts 19:21-22 explains:  writing from Ephesus, Paul had already sent Timothy toward Corinth the long way, overland through Macedonia, while the letter went by the direct sea route.  The letter would beat the messenger, and Timothy's exact itinerary was unsettled.  Acts states the travel arrangements without the letter's uncertainty.  The letter shows the uncertainty without the travel arrangements.¹

Erastus Stayed in Corinth

Acts and Romans explain 2 Timothy — Paul writes, "Erastus remained in Corinth."  (2 Timothy 4:20)  Why would Timothy care, and why is staying in Corinth worth reporting?  Acts 19:22 says Timothy and Erastus had been coworkers, sent together into Macedonia.  And Romans 16:23, written from Corinth, sends greetings from "Erastus, the city treasurer" — Corinth was Erastus' home and career.  A pavement inscription found at Corinth in 1929 reads "Erastus in return for his aedileship paved it at his own expense," showing a first-century official of that name doing public works there, though scholars dispute whether he is the same man.¹⁹

Aristarchus in Rome

Acts explains Colossians and Philemon — Writing from Roman custody, Paul calls Aristarchus "my fellow-prisoner."  (Colossians 4:10, Philemon 1:24)  How did this Thessalonian end up imprisoned with Paul in Rome?  Acts tracks him without comment:  seized in the Ephesus riot (Acts 19:29), traveling with Paul to Jerusalem (Acts 20:4), and boarding the prisoner ship for Italy (Acts 27:2).

Philemon Lived in Colossae

Colossians explains Philemon — The letter to Philemon never says what city Philemon lived in.  It greets Archippus (Philemon 1:2) and concerns the returning slave Onesimus.  Colossians, sent at the same time, calls Onesimus "one of you" (Colossians 4:9) and gives instructions to Archippus as a member of the Colossian church (Colossians 4:17).  Onesimus was being returned to his master, so his master lived in Colossae.  Jonathan McLatchie points out that the two letters were addressed to overlapping people yet neither states the connection.²⁰

In the Old Testament

Blunt devoted half his 1847 book to the Old Testament.  Six examples follow, in canonical order.

Who Plotted with Korah?

The camp lists explain Numbers 16 — Korah's rebellion against Moses was led by Korah, a Levite of the clan of Kohath, together with Dathan, Abiram, and On — Reubenites.  (Numbers 16:1)  Why would laymen of Reuben join a Levite's dispute over the priesthood?  Two dry administrative passages, thirteen and fourteen chapters earlier, answer it.  "The clans of the Kohathites were to camp on the south side of the tabernacle."  (Numbers 3:29)  "On the south side shall be the regimental encampment of Reuben."  (Numbers 2:10)  The conspirators were next-door neighbors.  Blunt:  "Surely this singular coincidence comes of truth — not of accident, not of design...  It does not come of design, for the agreement is not obvious enough to suit a designer's purpose — it might most easily escape notice."⁶

Rahab's Flax

Exodus and Joshua explain each other — Rahab hid the Israelite spies "with the stalks of flax that she had laid out on the roof."  (Joshua 2:6)  Why was there cut flax drying on a roof in Jericho just then?  Joshua 4:19 dates the crossing of the Jordan to "the tenth day of the first month" — four days before Passover.  Exodus 9:31, describing the plague of hail in Egypt decades earlier and for its own reasons, notes that just before that same season "the barley was in the ear and the flax was in bud."  Flax and barley ripen together in early spring.  So the spies arrived in the days of the flax harvest, exactly when fresh-cut stalks would be spread out on flat roofs to dry.  Blunt:  "Here I see truth.  Yet how very minute is this incident!  how very casually does it present itself to our notice!"⁶

Where Are Israel's Weapons?

The book of Judges and early 1 Samuel show Israelites repeatedly fighting without normal weapons, and never explain the pattern.  Ehud makes his own dagger for a single assassination (Judges 3:16).  Shamgar kills Philistines "with an ox-goad" (Judges 3:31).  Deborah's song asks, "Was shield or spear to be seen among forty thousand in Israel?"  (Judges 5:8)  Samson fights with a donkey's jawbone (Judges 15:15).  David faces Goliath with a shepherd's sling (1 Samuel 17:40).

A single verse, written to explain none of these, explains all of them:  "Now there was no blacksmith to be found throughout all the land of Israel; for the Philistines said, 'The Hebrews must not make swords or spears for themselves.'"  (1 Samuel 13:19)  On the day of battle "neither sword nor spear was to be found" with anyone except Saul and Jonathan.  (1 Samuel 13:22)  The Philistines ran a weapons embargo, and the odd armaments scattered across two books fit it.

Why Was Goliath from Gath?

1 Samuel 17:4 introduces "Goliath, of Gath, whose height was six cubits and a span" — a giant from one specific Philistine city.  Centuries earlier in the narrative, Joshua exterminated the Anakim, the giant clans of Canaan:  "None of the Anakim was left in the land of the Israelites; some remained only in Gaza, in Gath, and in Ashdod."  (Joshua 11:22)  Gath is one of the three named refuges.  2 Samuel 21:15-22 later mentions four more giant warriors:  "These four were descended from the giants in Gath."  (2 Samuel 21:22)  Neither Joshua nor Samuel connects the passages.

Why Did Ahithophel Turn Traitor?

2 Samuel explains 2 Samuel — When Absalom launched his coup against king David, his first move was to send for "Ahithophel the Gilonite, David's counsellor" — and he counted on Ahithophel's defection before asking.  (2 Samuel 15:12)  The text never says why the king's most valued adviser, whose counsel "was as if one consulted the oracle of God" (2 Samuel 16:23), turned on him.  Three scattered passages supply a motive.  The roster of David's elite guard includes "Eliam son of Ahithophel the Gilonite" (2 Samuel 23:34) and, five verses later, Uriah the Hittite (23:39) — fellow officers.  And Bathsheba was "daughter of Eliam, the wife of Uriah the Hittite."  (2 Samuel 11:3)  If the two Eliams are the same man — the rare epithet "Gilonite" ties them — then Bathsheba was Ahithophel's granddaughter.  David had violated Ahithophel's granddaughter and murdered her husband, the comrade of Ahithophel's son.  Blunt:  "when David murdered Uriah, he murdered Ahithophel's grandson by marriage, and when he corrupted Bath-sheba, he corrupted his granddaughter by blood."⁶  It even explains Ahithophel's first piece of advice:  that Absalom violate David's concubines in a tent "upon the roof" in the sight of all Israel (2 Samuel 16:21-22) — the palace roof where David's sin began.  (2 Samuel 11:2)²¹

The identification rests on equating the two Eliams; Blunt calls it "so probable, as almost to amount to certainty."⁶  It is an inference, not a statement of the text, and Chronicles calls Bathsheba's father Ammiel — the same two name-elements in reverse order.  (1 Chronicles 3:5)

Hezekiah's Refilled Treasury

Chronicles explains Kings and Isaiah — In 701 BC Hezekiah bought off the Assyrian invasion with "all the silver that was found in the house of the LORD and in the treasuries of the king's house," even stripping the gold off the temple doors.  (2 Kings 18:15-16)  Yet soon afterward — the Babylonian embassy arrived just after the illness that the text ties to the Assyrian crisis (2 Kings 20:6) — Hezekiah gave the envoys a tour:  "he showed them all his treasure house, the silver, the gold, the spices, the precious oil...  there was nothing in his house or in all his realm that Hezekiah did not show them."  (2 Kings 20:13, repeated in Isaiah 39:2)  How was the emptied treasury full again?  Chronicles, which mentions the embassy only in passing and never the treasure tour, notes what happened after Sennacherib's army was destroyed:  "Many brought gifts to the LORD in Jerusalem and precious things to King Hezekiah of Judah, so that he was exalted in the sight of all nations."  (2 Chronicles 32:23)  Kings and Isaiah record the display but not the refilling.  Chronicles records the refilling but not the display.²¹

One weakness:  Babylonian records end Merodach-baladan's rule before 701 BC, so some scholars date his embassy before the tribute rather than after it.  The coincidence holds on the sequence the text itself gives, but the external chronology is contested.

With Sources Outside the Bible

Why Josephus Links John the Baptist to a Military Defeat

The gospels explain Josephus — The Jewish historian Josephus records that around 36 AD the Nabatean king Aretas destroyed the army of Herod Antipas, and that "some of the Jews thought that the destruction of Herod's army came from God, and that very justly, as a punishment of what he did against John, that was called the Baptist."²²  Why would Jews link a border war with Aretas to the execution of a preacher?  Josephus gives the war's cause in the same passage:  Herod had agreed to divorce Aretas' daughter in order to marry Herodias, his brother's wife — and Aretas went to war over the insult.  The gospels, independently, say John the Baptist was executed precisely for condemning that marriage:  "It is not lawful for you to have your brother's wife."  (Mark 6:18, Matthew 14:3-4, Luke 3:19-20)  The dots connect only when both sources are on the table.

Objections

"The gospel writers copied each other"

Matthew, Mark, and Luke share so much wording that most scholars hold Matthew and Luke used Mark.  Atheist historian Richard Carrier presses this against the whole argument:  "This was an old preacher's argument from over a hundred years ago...  Which never caught on because objective scholars had already started concluding the Gospel authors know things about other Gospels because they read them, and they changed some of those things because they wanted to."²³  On the foot-washing coincidence his explanation is simple:  "John didn't like Luke's story.  So he replaced it with a different one."²³

Three answers:

1. Copying produces sameness, not interlocking halves. Lydia McGrew: "if you were writing a later document copying from that source, the natural thing to do would be to copy both points and point out the causal relationship between them. You're just copying, after all… But when you witness a reality, you may or may not make the causal connection yourself between two facts, or you may not remember it at all or with enough vividness to want to mention it."²⁴ A redactor who "replaces Luke's story" has no reason to write a replacement that happens to answer Luke's unanswered question.
2. The strong examples are chosen to survive Markan priority. McGrew states her selection rule: "I am deliberately taking care that the evidence brought forward in this book does not depend in any way on denying Markan priority in the order of the Synoptic Gospels or on denying the presence of any literary dependence among the Gospels."¹ A Matthew-explains-Mark case can't be copying from Mark, because Mark lacks the explaining detail. Erik Manning, using the paired-disciples example: "What truly matters is the casual way two accounts fit together. The key is their casual nature, the absence of deliberate attempts to corroborate each other, which provides evidence for their independence."²⁵
3. Blunt already assumed dependence. Jonathan McLatchie notes that Carrier's history is wrong: "Carrier falsely asserts that the argument from undesigned coincidences between the gospels was developed when it was believed that the four gospels were entirely independent of one another... But this is not true. John James Blunt... repeatedly writes in ways that reveal that he was perfectly comfortable with a literary relationship between the gospels."²⁶

"The interlocks only prove a common source, not a true story"

Carrier grants that some interlocks exist, then discounts them:  "But even such a theory as that only gets you to a source.  Not that source being true."²³  Bart Ehrman makes the same point with an analogy:  if two unrelated documents confirm that Ehrman lives in Durham and banks on a certain street, that doesn't prove a story that he robbed the bank:  "why would those undesigned coincidences show the story is true, and that I really did rob the bank?"²⁷

The response runs in two steps.  First, positing a lost common source behind the interlocks explains nothing the documents don't already explain.  McGrew:  "That hypothesis, then, merely adds a further, unneeded 'layer' between the documents we actually have and real events.  It is therefore in blatant violation of the maxim not to multiply entities without necessity."²⁴  Second, the argument's conclusion is calibrated to what interlocking can show:  that the accounts come from people close to real events who reported them truthfully in the details we can check.  Ehrman's analogy actually concedes this — the coincidences in his story really would confirm the incidental facts.  Whether general reliability plus many interlocks touching the miracles themselves supports the miracles is a further argument, and McGrew is explicit that no one claims "there's undesigned coincidence in a miracle account, therefore the miracle likely happened."²⁸

"John knew the Synoptic Gospels"

Duke scholar Mark Goodacre argues in "The Fourth Synoptic Gospel" (2025) that John knew and used Matthew, Mark, and Luke.²⁹  Carrier:  "John repeatedly riffs on Luke this way, often to reverse or change a point Luke made, which is how we know John knows Luke (they are not writing independently)."³⁰

If John wrote with the Synoptics open in front of him, the puzzle gets worse, not better.  A writer using Luke should reproduce Luke's information, not leave gaps that only Luke fills and fill gaps only Luke leaves.  And John — on all accounts the latest gospel — has the most unique undesigned coincidences of the four.  McGrew:  "This does not fit any pattern that treats Mark, the shortest Gospel, as the most factual or that treats later Gospels as literary or redactive alterations of Mark."¹

"Apologists count the hits and ignore the misses"

Carrier's summary verdict:  "The Argument from Undesigned Coincidences is basically tinfoil hat.  It lacks any scholarly basis, is completely devoid of methodology, and is mostly delusional.  Many of the claimed coincidences don't even exist.  Some are obviously just coincidences (some may even be copying errors)."²³  Michael Alter's "The Hypothesis of Undesigned Coincidences: A Critical Review" (2024) is the only book-length critique, working through the examples case by case.³⁰  A gentler version comes from John Nelson, a Christian with a PhD in Christian origins from Edinburgh, who accepts the argument in principle but writes:  "much which passes for 'undesigned coincidences' in the gospels eludes that descriptor.  That is, a closer examination of the gospels reveal that 'undesigned coincidences' are often easily explained by the kinds of redactional interests, compositional practices, or points of context which have been traditionally highlighted by gospel scholars."³¹

Nelson's point lands on some examples, and the honest response is to prune — as McGrew did, cutting examples explainable by copying,¹ and likewise as this article does.  Notably, when Carrier attacked specific examples, three of his targets were ones McGrew's book had already declined to use.³²  But pruning is not surrender.  The argument is cumulative, and the surviving core — interlocks running in both directions between all four gospels, Acts, and the letters — still needs an explanation.  Selection bias cannot explain why the explanations exist at all; a fictional corpus offers nothing to select.

What about the contradictions?

Skeptics also ask why interlocking details should outweigh the apparent contradictions between the same books.  The two phenomena are not symmetrical.  Discrepancies in secondary details are the normal texture of independent testimony — Paley's "substantial truth under circumstantial variety."⁴  Wallace, from casework:  "an eyewitness account can be reliable in spite of apparent contradictions.  While we might complain about two accounts that appear to differ in some way, we would be even more suspicious if there were absolutely no peculiarities or differences."³  Indeed the differences are the core of this argument:  accounts that diverge in wording and selection clearly were not harmonized, which is what makes their interlocking hard to explain by design.

Weak Examples

Honesty requires pruning.  Some proposed coincidences are too thin to carry weight, and including them damages the strong ones.

• Alexander the coppersmith. Paul warns Timothy about "Alexander the coppersmith" (2 Timothy 4:14) and had earlier "turned over to Satan" an Alexander (1 Timothy 1:20). Alexander was among the most common names in the empire, and the accounts connect too loosely to interlock.
• Timothy's timidity. 1 Corinthians 16:10 ("see that he has nothing to fear") is sometimes linked to Paul's remarks about Timothy's youth (1 Timothy 4:12). The connection is possible but adds little; the itinerary coincidence above is the strong one in that verse.
• Synoptic pairs where Mark holds both halves. Besides the sunset healing above, McGrew excludes "who struck you?" (Luke 22:64 explaining Matthew 26:68) and the disciples' silence after the Transfiguration (Matthew 17:9 with Luke 9:36), because in each case Mark contains enough that copying could explain the fit.¹

Sources