A Refutation to John 5:2 – https://biblicalfoundations.org/was-johns-gospel-written-prior-to-ad-70/
Peter Walker, in his important book Jesus and the Holy City (Eerdmans, 1996, p. 197), says it well:
“As a result, if any of his readers felt bereft of the Temple and of the spiritual focus provided by Jerusalem, John would have encouraged them not to mourn the loss of the city, but rather to see what God had done for them in Jesus. . . . The Evangelist, writing after the Temple’s destruction, does not bemoan its loss. . . . The presence of God has not been withdrawn, for Jesus has taken the place of the Temple. Jesus gives more than the Temple had ever given. . . . Jesus stands in the place of everything that Israel has lost.”

Dating the Gospel of John to after AD 98 📜
A. Internal Evidence #1: No warnings to flee the destruction of Jerusalem which was only 4-8 years away when John supposedly wrote the book before AD 70:

No mention of future destruction of Jerusalem, which for Full-Preterists is odd, since John writes the entire book of Revelation about it and the topic would be front and center on his mind that is only 2-4 year away.
B. Internal Evidence #2: John 21:20-23 proves the gospel of John was written long after AD 70
“Lord, and what about this man?” Jesus said to him, “If I want him to remain until I come, what is that to you? You follow Me!” Therefore this saying went out among the brethren that that disciple would not die; yet Jesus did not say to him that he would not die, but only, “If I want him to remain until I come, what is that to you?”” (John 21:20–23)

John 21:20-23 proves the gospel of John was written long after AD 70 because the disciples would never have fabricated the notion that John would be “an eternal” and live past the normal age of life. The rumour that went out among the brethren was unique to John, in spite of the fact that in AD 66 he was likely about 66 years old. The rumour was special to John because many of the young 20 year old disciples baptized in AD 60 also believed that John would even outlive them! The only way it makes sense is if John is very old, like 100 years old, having outlived all the other apostles. Obviously then, the rumour that John would never die began to be widely believed in AD 98 AND FOR GOOD REASON, or so they thought, when he wrote the Gospel of John. This perfectly explains why John felt the need to discuss this rumour about him when he wrote the Gospel of John in AD 98. Having outlived all the other apostles to the age of 100, this fact was the evidence all the Christians pointed to that John, unlike all other men, would live till the second coming as an “eternal”.

John 21:20-23 is utterly devastating to Full-Preterists because not only will John outlive Peter, but Peter will die when he is old, which means Peter did not expect the coming of the Lord in his lifetime. Peter was likely only 70 in AD 70.
Of course, when John is almost 100 years old and wrote the Gospel of John around AD 98, he likely was the last apostle alive of the 13 and therefore the rumour became widely believed and was becoming a problem that needed fixing. This is why John felt the need to quell the rumour, because he had outlived most of the apostles by close to 40 years.

John 21:20-23, when properly expounded triggers a catastrophic collapse of Full-Preterism because it proves:
a. That the “coming of the Lord with clouds” had two distinct applications: AD 70 and the Second coming after that when John was alive in AD 98.

b. The Gospel of John was written after AD 70.

c. The Second coming of Christ was still expected after AD 70.

d. That Peter was aware of the “Lord come quickly” passages but did not expect to be alive, even in old age, for the second coming.

e. Peter understood that John was the only man on earth before AD 70 with a supernatural life expectancy that enabled him to see the second coming. John’s Natural life was 100 years of age in 100 AD. The disciples expected John to supernaturally outlive EVERYONE alive in AD 33 to see the second coming. There is nothing unique or unusual about John being alive in AD 70 because many others alive in AD 33 also lived past AD 70. Therefore the “coming of the Lord” the disciples believed John would experience as an “exceptional eternal” must be well past his natural life’s expectancy, after AD 70, well into the middle of the second century.

f. The elephant in the room, is that no one would equate living past AD 70 as uniquely remarkable for John alone, since children and most of the Christians alive in AD 30 would also live as long or longer than John.

g. Even if the gospel of John was written in 60/61 AD, John was still universally believed at this late date, to supernaturally outlive his own natural time of death. AD 70 was earlier than John’s natural life expectancy so the phrase, “he would not die” can only mean that the disciples expected John to live long past AD 70 to see the second coming of Christ.
C. Internal Evidence #3: The Gospel of John was NOT written for Jews in Jerusalem because he translates Hebrew words for the Greeks. (see section above)
D. Internal evidence #4: John 5:2 does NOT prove John was written before 70 AD:
THE TEXT: “Now there is [Strongs # 2052] in Jerusalem by the sheep gate a pool, which is called in Hebrew Bethesda, having five porticoes.” (John 5:2)

False Argument: If John was written after 70 AD John 5:2 would NOT SAY, “There IS (present, not past tense) in Jerusalem, the pool of Bethesda”.

a. It would read: “There WAS”.

b. This is faulty reasoning based upon tense because even it the pool had been destroyed, he would simply be looking back into the past when the pool existed. But as we will see, the pool continued to be in use until the 6th century AD and was never destroyed.

If the present tense “there IS a pool” proves John was written before 70 AD, then using this same logic, John’s use of pasts tense, proves it was written after 70 AD:

a. Was the water gone after 70 AD? “John also was baptizing in Aenon near Salim, because there WAS much water there” (John 3:23)

b. Was Jacob’s well destroyed? No! In fact, you can still visit it today at Nablus, Israel: “So He came to a city of Samaria called Sychar, near the parcel of ground that Jacob gave to his son Joseph; and Jacob’s well WAS there.” (John 4:5–6)

c. Is Bethany today, no longer NEAR Jerusalem! “Now Bethany WAS near Jerusalem, about two miles off;” (John 11:18)

d. This verse must surely prove John was written after 70 AD because it says the Garden where Jesus prayed no longer existed! “When Jesus had spoken these words, He went forth with His disciples over the ravine of the Kidron, where there WAS a garden, in which He entered with His disciples.” (John 18:1)

e. As you can see, these arguments based upon tenses used when narrating an historical event are weak and worthless. As you can see, there is no consistent pattern of John using present tense to refer to still valid geographical and architectural facts when he wrote the book in 100 AD, and the past tense for things destroyed.
Josephus records how Titus was careful to preserve the Temple and city, doing as little damage as possible to preserve the city for Rome to use:

a. The Pool of Bethesda: “The Architectural style and inscription point to Herodian times, making it one of the many magnificent building projects of Herod the Great. (Baker Encyclopedia of the Bible, Beth-zatha)

b. After setting the outer porticos of the Temple on fire, Titus then order fire extinguishers to save the temple itself and then holds a conference with his generals who all decide NOT to destroy the temple but to put out the fires:
a. “Titus proposed to these that they should give him their advice what should be done about the holy house. (239) Now, some of these thought it would be the best way to act according to the rules of war [and demolish it]; because the Jews would never leave off rebelling while that house was standing; at which house it was that they used to get all together. (240) Others of them were of opinion, that in case the Jews would leave it, and none of them would lay their arms up in it, he might save it; but that in case they got upon it, and fought any more, he might burn it; because it must then be looked upon not as a holy house, but as a citadel; and that the impiety of burning it would then belong to those that forced this to be done, and not to them. (241) But Titus said, that “although the Jews should get upon that holy house, and fight us thence, yet ought we not to revenge ourselves on things that are inanimate, instead of the men themselves;” and that he was not in any case for burning down so vast a work as that was, because this would be a mischief to the Romans themselves, as it would be an ornament to their government while it continued. (242) So Fronto, and Alexander, and Cerealis, grew bold upon that declaration, and agreed to the opinion of Titus. (243) Then was this assembly dissolved, when Titus had given orders to the commanders that the rest of their forces should lie still; but that they should make use of such as were most courageous in this attack. So he commanded that the chosen men that were taken out of the cohorts should make their way through the ruins, and quench the fire.” (Josephus Wars 6.238-243, 5th August AD 70, Sunday, 9 Lous/Av)

b. “Caesar gave orders that they should now demolish the entire city and temple, but should leave as many of the towers standing as were of the greatest eminency; that is, Phasaelus, and Hippicus, and Mariamne, and so much of the wall as enclosed the city on the west side.” (Josephus Wars 7:1, 2nd September AD 70, Sunday, Gorpiaeus/Elul 8)
Eusebius describes the pool of John 5:2, as not only still in use in AD 325, but as being architecturally identically as well.

a. “Bēzatha (Bethsaida). Pool in Jerusalem which is (called probatike and interpreted by us) “sheep.” Once it had five porticos. There are now pointed out twin pools, of which one is filled by the rain water (winter rains) and the other it appears that the water becomes miraculously red, as they say, bearing the traces of the sacrificial victims formerly washed in it. So it is called the sheep after the sacrifice. (Red like blood which in itself is seen as a sign of old. The sacrificial victims were brought unbound by the priests into the bath, whence it received its name.) Modern Footnote: This explanation is curious. Such explanations are not common in the Onomasticon. In Eusebius only one of the twin pools is involved in the miracle. The pilgrims report similar happenings. “There are in Jerusalem two large pools at the north side of the temple, that is one upon the right hand and one upon the left where were made by Solomon; and further in the city are twin pools with five porticoes which are called Bethsaida. There persons who have been sick for many years are cured; the pools contain water which is red when it is disturbed” (Itin. Bourd. PPT 1, 20). (Eusebius, Onomasticon, 325 AD)
The Pool of Bethesda was in continuous as a Roman cult centre for healing from AD 135 down to at least the 6th century AD:

a. “Confirmation that a local healing cult continued into the 2d century comes from archaeological excavations at the site (Duprez 1970). Votive offerings characteristic of grateful devotees of Serapis or of Asclepius were unearthed in the debris in the double pool. Thus the local cult assumed Roman dress when Roman cults appeared in the new city of Aelia Capitolina. Aelia replaced Jerusalem under the emperor Hadrian in 135 C.E. after the Second Jewish Revolt against Rome. The site would therefore have become part of the Roman cult, namely, a Serapeum or an Asclepium, which may account for the underground chambers at the site. Further evidence for the continued importance of the site is the erection of a Christian church in the 5th century just E of the pool. Its courtyard school on arched pillars and buttresses directly over the E end of the double pool. The presence of the church would overthrow and obliterate the local cult.” (ABD, Beth-Zatha)

Conclusion: The Pool of Bethsaida was not destroyed in AD 70 but preserved by the Romans and continued to be used for centuries afterwards.
E. Eusebius: External Literary Source #1: Eusebius says the Gospel of John was written at Ephesus in AD 100:
Eusebius says John was the last gospel

a. “And when Mark and Luke had already published their Gospels, they say that John, who had employed all his time in proclaiming the Gospel orally, finally proceeded to write” (Eus., Hist. eccl. 3.24.7)

The silence of the literary sources that document such a major event as the rapture of every Christian on earth in AD 66 SCREAM FICTION as loudly as the lack of archeological evidences for the Book of Mormon, especially when the actual literary sources we do posses vociferously contradict this fiction.

“At this time, in Asia, that very disciple whom Jesus loved, at once both Apostle and Evangelist, was still alive and administered the churches there, having returned from his exile on the island after the death of Domitian [AD 98, is the date exile ended, not when Revelation was written 32 years earlier in AD 66] It is enough to confirm the report that he still survived at this time through two witnesses, and these should be trustworthy, for they represented the orthodoxy of the Church; such, indeed, were Irenaeus and Clement of Alexandria. The former of these, in Book 2 of his work Against Heresies, writes word for word as follows: ‘And all the presbyters who had associated in Asia with John, the disciple of the Lord, attest to John’s tradition, for he remained with them until the times of Trajan.’ And in Book 3 of the same work he discloses this same fact in these words: ‘Moreover, the Church at Ephesus, which was established by Paul and where John remained with them until the times of Trajan, is a true witness of the tradition of the Apostles.’” (Eus., Hist. eccl. 3.23)

“Afterwards, John, the disciple of the Lord, who also had leaned upon His breast, did himself publish a Gospel during his residence at Ephesus in Asia.” (Iren., Adv. Haer. 3.1.1)

Polycarp says Apostle John lived during Caesar Trajan (AD 98-117)
a. Polycarp who was born in AD 81 and died in AD 167, had personally met and been taught by Christians who were eyewitnesses of Christ before AD 33.

b. Polycarp suffered about the year 167, in the reign of Marcus Aurelius. His great age of eighty-six years implies that he was contemporary with St. John for nearly twenty years.

c. “But Polycarp also was not only instructed by apostles, and conversed with many who had seen Christ, but was also, by apostles in Asia, appointed bishop of the Church in Smyrna, whom I also saw in my early youth, for he tarried [on earth] a very long time, and, when a very old man, gloriously and most nobly suffering martyrdom, departed this life, having always taught the things which he had learned from the apostles, and which the Church has handed down, and which alone are true.” (Iren., Adv. Haer. 3.3.4)

d. “There are also those who heard from him (Polycarp) that John, the disciple of the Lord, going to bathe at Ephesus, and perceiving Cerinthus [heretic] was inside, rushed out of the bath-house without bathing, exclaiming, “Let us fly, lest even the bath-house fall down, because Cerinthus, the enemy of the truth, is within.”” (Iren., Adv. Haer. 3.3.4)
i. When Full-Preterists dismiss Polycarp on the basis that an old man could not run, they are confusing John for Peter, whom John clearly outran to the tomb in 5 April AD 33.
ii. “So Peter and the other disciple [John] went forth, and they were going to the tomb. The two were running together; and the other disciple ran ahead faster than Peter and came to the tomb first; and stooping and looking in, he saw the linen wrappings lying there; but he did not go in. And so Simon Peter also came, following him, and entered the tomb; and he saw the linen wrappings lying there,” (John 20:3–6)
iii. So the only detail we know about any of the apostles physically is that John was the fastest runner! Ouch to Full-Preterists!